Surface Plasmon Resonance - Science method

Pulak Ghosh

Surface plasmon resonance or plasmons occur on the surface of nanoparticles with an Al/O ratio of 1. Your aluminum oxide has a different stoichiometry and is unlikely to have plasmon resonance.

I would like to know if you have found anything yet

Please make your plant extract alkaline first (pH~10). Then add dilute silver nitrate solution to this plant extract. If you want to synthesize AgNPs at room temperature, then you can use more alkali. Before taking UV spectra you have to wash the particles properly to remove excess plant extract and alkali.

Hey there Michelle Darmawan,

When it comes to detecting the presence of silver nanoparticles (AgNPs), the appearance of a peak in the UV-Vis spectrum around 380-420 nm is often cited as an indicator. However, the tolerance limit for the lowest wavelength peak, even if it shows a blue shift, can vary depending on the specific synthesis method and the characteristics of the nanoparticles. Generally, a blue shift in the peak could still suggest the presence of AgNPs, but the exact limit would require careful experimentation and validation.

Regarding the timing of characterization, it's commonly recommended to conduct UV-Vis analysis around 24 hours after the synthesis of AgNPs. This timeframe allows for stabilization and aggregation of nanoparticles, ensuring a more accurate representation of their optical properties. However, this timing can also depend on factors such as the synthesis protocol and the intended application of the nanoparticles.

In summary, while a single peak around 380-420 nm is often associated with AgNP formation, the tolerance limit for the lowest wavelength peak may vary. Additionally, conducting UV-Vis characterization approximately 24 hours after synthesis is a common practice to ensure reliable results. As always, it's essential to consider specific experimental conditions and consult relevant literature for further guidance.

Hope this helps! Let me know if you Michelle Darmawan need more info. Cheers!

Michelle Darmawan

It is necessary to check the plasmonic absorption of nanoparticles in the dispersion. If there is, then centrifuge additionally or let it sit for a week.

Michelle Darmawan

It is necessary to understand the solution to the problem using methods

1.UV-Vis. You determine the amount of absorption from the interaction of plasmons of nanoparticles in the visible region and prove, by comparison with other studies, that you have nanoparticles. If you reduced with hydrazine or borohydride, then you don’t have to dry the dispersion. If you restore with leaf extract, then there may be the presence of coloring substances that can change the plasmon band.

2.FTIR. You determine the presence of functional groups after the reaction. It is necessary to work with dispersion.

3.DLS. It is necessary to work only with a stable dispersion without agglomerates.

4.SEM/TEM. Prepare the dry film so that it is sparse and individual nanoparticles are visible. The sample will be placed in a vacuum and therefore must be dried under vacuum in air. Do not heat.

No one should be working with metallic nanosystems without knowing about stabilization agents, zeta potential, surface charge, oxidized ions, dissolved oxygen, electrostatic stabilization, steric stabilization, etc.

In my opinion, first of all, you should be familiar with the concepts of SPR and the governing equations. When you are familiar with these equations, MATLAB programming will not be a problem. Implementing the desired relationships in MATLAB is an easy task, you can get help from MATLAB programming courses on the Coursera website. At the same time, you can get good content by searching among related articles.

İletim ve taşıma

2D materials may improve surface plasmon resonance sensitivity, tunability, selectivity, optical phenomena, and integrated device designs. Their unique features and ease of functionalization make them useful tools for enhancing SPR-based sensors.

Her yüzey alanı için bir rezonans aralığı olmalı ve bunları ölçecek ayrı ayrı sensör olması gerekiyor.

Hi Nelly. I think it is going to be difficult. Without regeneration and complete dissociation you are basically performing a so called single cycle kinetics experiments which is a patented approach and therefore, data analysis is not available. You could run low but non-zero concentrations in between your concentration series and use TraceDrawer. Alternatively, you could use Interaction map for data analysis. Best, Jos

Dear friend Sivasakthi Paramasivam

The s-CM5 sensor chip is commonly used for surface plasmon resonance (SPR) analysis to immobilize proteins for binding studies. The chip surface is coated with a thin layer of carboxymethylated dextran, and proteins are immobilized on the surface through covalent coupling or non-specific adsorption.

To store the protein immobilized s-CM5 sensor chip, it is recommended to use a buffer that is compatible with the immobilized protein and will not cause significant degradation or denaturation of the protein. HBS-EP buffer (10 mM HEPES pH 7.4, 150 mM NaCl, 3 mM EDTA, and 0.005% Tween-20) is a commonly used buffer for storing immobilized proteins on SPR sensor chips. This buffer helps to maintain the stability and activity of the immobilized protein over time.

For long-term storage of the protein immobilized s-CM5 sensor chip, it is recommended to store the chip in a sealed container or bag with the HBS-EP buffer at 4°C or -20°C. The storage time depends on the stability of the immobilized protein, but it is generally recommended to use the chip within a few weeks to a few months of immobilization to ensure optimal binding activity.

Did you find the solution? I am in the same trouble.

Yüksek plazmonik mod yüksek rezonanslarda ve herhangi bir zamanda rezonansın yüksek olduğu noktada ortaya çıkar. Rezonansın çekirdek çapıyla pek bir bağıntısı yoktur.

How is Comsol simulation different from fdtd simulation?

Comsol 5.5

Please use this (https://www.sprpages.nl/sensor-chips-intro) as a starting point.

Arnoud

Hello Archana Tripathi

The smaller the Kd value, the greater the binding affinity of the ligand for its target. For peptides, the Kd value falls into the range from micromolar to nanomolar. Higher binding affinity leads to a higher dynamic concentration of binding ligand on the target and longer retention time for ligand-receptor interaction, which theoretically will enhance the drug delivery.

The cellular uptake of the peptide can be divided into three steps, 1) binding, 2) internalization, and 3) exerting cytotoxicity. Therefore, to kill the cancer cells, a peptide needs to first bind to the receptor on the target cellular membrane.

To enhance the drug delivery, the binding affinity should fall in the range of nanomolar, and higher binding affinity would contribute to higher cellular binding, drug delivery efficiency and selectivity, and a higher rate of cellular uptake.

Your peptide has Kd value (in nM range). So, it will have higher binding affinity and would contribute to the higher efficiency of cytotoxic agent delivery. But not always necessary that it may show enhanced cytotoxicity. There are peptides that have shown lower drug delivery efficiency but still have enhanced cytotoxicity.

So, I would suggest besides nM dose ranges, you should also try to go up to uM dose ranges to get an IC50 value.

Best.

Have a look at this paper, which explores surface plasmons in Cu nanowires:

Thank you for the suggestions and the additional data, Hugh J Byrne and Jürgen Weippert. I was aware that absorption below 400 nm is considered as non-reliable.

A comparison of these spectra with the absorption of the respective carboxylic acids was also not providing clear correlations. That is why I felt that something else might happen.

Moustafa, hard to judge since the instrument type used is unknown. The solid lines seem to be the recorded data (including huge buffer shifts), the dotted lines seem to show fitting trials that ignore the buffer shifts. - You should ask the person (from whom you received the data) for details about data recording and fitting parameters.

Dear all, please search using 'attenuation of Surface Plasmon Resonance', many investigations are available. Please have a look at the following documents, hope they will be usefull somehow. My Regards

I agree with Vanessa Porkolab.

In the past, I did coated my plastic fibers with gold and it worked very well. Let me know if you want to know more.

Dear

Thanks for your complete answer.

In fact, I thought about the hot electron injection to the substrate.

As we're expecting localized or propagating plasmons in graphene, isn't it possible to have electron leakage from the graphene to high doped substrates? Instead, SiO2 or other insulators offer electrostatic charge transfer, which may facilitates the graphene-graphene hybridization in periodic structures like 1D graphene ribbons. Is this a valid claim?

Hello Angad Sir,can you please provide the code?

Apart from suggested resources above, this course is very helpful:

Xu Xuanwen, A well-localized, evanescent SPR field is excited surface absorbed molecules. Then this field is re-emitted due to their own oscillations with a frequency of incident light. These oscillations are specific to the kind of absorbed molecules, their index of refraction, concentration (so, SPR intensity), other optical properties. In such a way, absorbed molecules influence on optical properties of the whole SPR system.

Strong surface localization of the SPR field produces strong sensitivity to only surface absorbed molecules and their state, which can be changed due to some specific reaction. Such effect is the origin of SPR application as chemical, biological sensors of different kinds.

the surface plasmon resonance occurs when polarized light incident on metal interface at different refractive indices.At a certain angle of incidence, the light energy interaction with the electrons in the metal surface layer

Dear Mariana J. Do Amaral, it was an experiment I was trying to do a long time ago. Unfortunately, I had to move on to other experiments as it was taking a long time to standardize. However, the main problem I was facing was the magnesium ions in my running buffer as far as I can remember. Magnesium being a divalent cation was probably binding to the NTA chip surface, giving negative RU. I also had cobalt ion in the buffer containing the his-tagged protein. Besides, ribosomes being such a big molecule needed more standardization which I didn't pursue. However, as far as I can remember, all the above suggestions from other people help understand the crucial points one needs to follow in order to standardize the experiment which I left inbetween.

This and following articles exactly related to answer on your question; I try to give it in very concise form, but there you can find complete one

BLI uses substantially more sample volume (something like 20-40uL in 384well, more like 100-200 in 96well), but like others have said, is *mostly* non-destructive (depending on how robust your sample is to agitation and ambient temperatures). BLI is less sensitive than traditional SPR (not suited to fragment screening and other small molecule apps) but is more amenable to crude samples such as sera/lysates etc since the tips are disposable. It's much faster for high-throughput type apps (especially if you can get your hands on the 96-channel top-of-the-line models), and so potentially much faster. Both systems need some amount of knowledge to be used properly. SPR can do some more complicated and interesting things (e.g. enzyme kinetics if you have at least a 4-surface consecutive flow system) and generally more robust data, but more finicky when it comes to troubleshooting. SPR can also be end-coupled to mass spec in some configurations.

Liposomes is a bit vague - is your protein embedded in the liposomes? or you are looking simply at protein-membrane binding? Either way you could have options with both SPR and BLI but you would need to optimize for your application. My personal recommendation is SPR but it may not be entirely objective ;)

Hope this helps

Hi Dr Martin Rosellen . I hope the following links could help:

1.

2.

Thank you @Yuri Mirgorod and @Sakshum Khanna for the enlightning explanation.

Does the addition of Ag NPs surface had a role for the decrease in absorption centre? Or it is from Ag+ ion?

Dear Surbhi Sharma , there are plenty of articles describing metallic NP´s size effects on localized surface plasmon resonances (LSPR). As a rule of thumb you can consider that the larger the particle the more red-shifted will be the LSPR. A way to understand this is by considering the metallic NP as a resonance box, in a "tiny" NP the light will be bouncing up and down in a tiny space, so short wavelengths will be in resonance, while in "big" NP´s light could be bouncing in a "large" space and therefore in resonance with larger wavelengths.

Normally your NP´s are not monodispersed, so there is a size polydispersity, and therfore the response of your mixture will be a mixture of the response of your particles according to their distribution. Not just size matters, also the shape of NP´s have an effect on the SPR´s of NP´s, for instance, a rod-like NP will show a double peak or band spectrum, indicating the presence of two resonances, one in the short direction (tranverse) and another in the long one (longitudinal).

May be the following research works, could be illustrative of the literature about this tipic:

You even can choose the NP´s by their size or their SPR wavelength:

RG let you search directly bibliography or questions already solved about any topic of your interest:

Hope this helps. Good luck with your research work.

Daer Ketan Karkare

To start with and to get an insight into the field of Plasmonics, my advice is to start by reading good review articles on Plasmonics. These will really help you to get acquainted with the recent happenings in the field and motivate you to think about the real problem and opportunity at hand.

At the same time, the book suggested by is really good for learning the concepts required for reserach.

Some of the important papers are attached for your help.

Thank you.

Dear Simón Roa , they are already having a relevant role in our times, specially for detection of SARS-CoV2 in a fast and sensitive way. This approach is not new and plasmonic sensors have been used to detect virus, bacterias and biomarkers for cancer or other patologies or just to measure biomolecules. Please, have a look to the following recent reviews you may find useful:

Combination of the high sensitivity of SPR with the structural information (and sensitivity) provided by SERS in a label free way, allow to widening their range of applications beyond biosensors, and actually they can be applied for detection of almost any molecule and in any field of study. Think for instance about the systems for detection of life biomolecules or life signatures in Mars or other planets or in the space.

Some of these life-related molecules could be chiral and new sensors with chiral properties could be useful for their detection.

An extensive review (about SERS) present and future applications you could find interesting is the one from 2020 in ACS-Nano, signed by good share (but not all) of the more prominent authors in the field at the time:

Additionally the introduction of new materials and alloys or composites together with new designs of nanostructures or metasurfaces is widening the range of applications. New spectrometers and softwares are key elements to improve the scope and power of the field.

My own expertise is related to the design and fabrication of these kind of sensors (SERS) and we have applied them to a variety of analytes, some already recorded in our work and some still in progress, including some biomolecules.

The potential of the field is what makes it so appealing.

Hope this helps.

Hi, as I know there is not such a module in COMSOL. but two modules can be used for Surface plasmon simulation. 1. RF module 2. wave optics module. there are different examples of the surface plasmon-related problem in the COMSOL application manager that you can use.

Dear Ambar Shukla , I agree, when one is starting in this field the terms couls be puzzling.

-Not any surface can produce plasmons, you need free electrons to cause the oscillation, so a metal or an electron rich material would be necessary.

-To many and for the sake of simplification SPR and SPP are synonyms, look for instance:

https://link.springer.com/referenceworkentry/10.1007%2F978-1-4419-8071-7_189#:~:text=A%20surface%20plasmon%20polariton%20(SPP,electrons%20excited%20by%20electromagnetic%20radiation.

However, I think that Peter Y. Yu answer is more accurate, since you can excite a plasmon polariton with an electromagnetic (EM) wave or with a beam of electrons.

About the relation of plasmons with dipoles, when a metal or plasmonic material is exposed to an EM wave, the electric field polarizes the charges into the metal, causing a dipole (induced by the field). This is often represented with metal nanoparticles with sizes smaller or close to the wavelength, but it is also applicable to surfaces or interfaces, just that in these cases the wave propagation left an alternating charge separation along the surface.

Hope it helps.

Hi Devi,

Lumerical software has a bunch of "example" simulation you can try from their fresh installed. The simplest way to start, you call one of this sample, take a look at the simulation design and condition, and how it works then try to modify and to your own case, you can change the material, or change the shape, or size (step by step). Do not forget to "save as.." to the new file name in your common folder.

Then try to run, and you got your first simulation case on Lumerical. If the error appears, you need to trace back from the example file, what was the mistake, then try to fix the error.

Good luck.

Seemesh Bhaskar has gone a long way to answering the question.

It should be added that, whereas transitions between Molecular orbitals or semiconductor bands, as a result of the absorption of a photon, are usually considered to involve single electrons, whereas a plasmon is a collective excitation of electrons, which in nanoparticles of metallic elements, is localised on the surface. Thus, light of appropriate wavelength/frequency/energy excites a surface plasmon resonance.

Dear Imran Ali ,

Typically the term “Surface plasmon resonance” is mainly used for the excitation of Surface Plasmon Polaritons in thin films, i.e. propagating plasmons, and you need some strategy (for instance, using a grating) to achieve the coupling, i.e. to increase the momentum.

On the other hand, the term “localized surface plasmon resonance” (LSPR) occurs in metallic nanostructures. LSPRs depend on the material (1), the dimensions (2) and the shape (3).

1) If you have nanospheres with the same diameter but some made of silver and others made of gold, the former would exhibit the LSPR peak at higher energy (lower wavelength).

2) If you have nanospheres made of the same material but some with diameter d1 and others with diameter d2, with d2>d1, the LSPR peak of d1 nanospheres would appear at higher energy (lower wavelength).

3) If you have a collection of identical aligned nanorods made of the same material, you would have two LSPR peaks depending on the light polarization: one along the rod axis and another along the perpendicular direction; the latter would appear at higher energy (lower wavelength).

Hi. I use piranha solution to clean of the chip that is covered by biomaterials. But, when I put it in solution all of my gold layer is dissolved in solution.

Do you have any idea about it and what I have to do?

Best sincerely

This paper provides very detailed definition:

Opt Express. 2008 Jan 21; 16(2): 1020–1028.

doi: 10.1364/oe.16.001020

You can remove any organic layer from a gold surface by "Piranha solution".

However, you should consider that this solution is quite dangerous, potentially damages the slide, and may be difficult to dispose. In your case, it might be not worth the effort.

Dear Nirmal Pol ,

For specific gas sensing applications of SPR, an ‘‘active sensing layer’’ is needed onto the Au transducing substrate. Its active role consists of the change of its optical constants upon the interaction with the analyte gas which can be sensitively detected as a change in the reflectivity SPR curve. For instance, in this work, a nanoporous columnar TiO2 layer has been chosen as sensing material to detect the presence of different alcohol vapours:

In fact, the transducing substrate is not only Au but a multilayer Au/Co/Au, so besides the SPR curve, also a Magneto-Optical SPR signal can be measured.

A similar approach has been used to detect amines in vapour phase, in this case with zinc porphyrin dimers as sensing layer:

Dear Mingyu Kwak,

From your spectra, you seem to use ethanol as a baseline rather air. This can cause a problem due to the nature of the calculation from the software in the spectrophotometer.

Please be aware of the measurements in the spectrophotometer are the transmission spectra. The absorbance is derived from the transmission spectra using software. For the liquid sample measurements, you should use the baseline of air, which means that when you set the parameters of equipment, you should set transmittance and both sample beam and reference beam are empty to scan the baseline. After that, measure the transmission spectrum of the solvent you use. Then measure your sample in the same solvent.

Finally, you can extract the sample transmission spectra. Then convert the transmission spectra into absorption spectra. In this way, you can gain the nature of your sample absorption spectra.

Hello dear,

You can visit my personal researchgate page, I think you wil find tha answer by reading some of my articles.

Dear Angana Bhattacharya,

You can take the limits for the triple integration as it includes a unit cell of your structure. In other words, you can take a volume large enough to envelop your structure. Because the current density is calculated by 𝑱(𝒓)=−𝑖𝜔𝜀₀(𝑛²−1)𝑬(𝒓), after all, the value becomes zero outside your structure.

The actual procedure can be found in our program paper.

Hope this helps.

As Vanessa Porkolab already explained correctly, you are observing avidity-based binding of bivalent antibodies. To overcome this problem, there are at least two more options:

1. You reduce the density of your antigen on the surface.

2. You cleave the antibody enzymatically in monovalent Fab fragments.

I have prepared Molecularly Imprinted polymer based surface plasmon resonance sensor for the detection of Tetracycline. Then I have compared the selectivity of my tetracycline sensor towards other structural analogues. Now I need to calculate the selectivity and relative selectivity of sensor.

Dear Moinul,

You can look into the following article for your answer.

Drude-Lorentz parameters are given in eV in this article.

You can also use https://refractiveindex.info/ which is also helpful.

Dear Parastou, I agree with Michael. The Thermo protocol may be the best from a purely chemical coupling point of view. The Biacore protocol favours concentration enrichment of protein ligand close to the surface. Simply try a few different pH values according to the different protocols, and most likely you'll find something that works well. Best, Anders

1) Allotrope variation: a plasmon energy is characteristic of the allotrope, so that's a "exists" vs. "doesn't exist" differentiation. An extreme example would be carbon: diamond does not have π states, so the π shakeup you observe for graphite or nanotubes isn't observed, of course.

2) Crystallinity: since plasmons are features associated with periodicity, I would expect stronger plasmon loss features for single-crystalline materials. I don't have data on it, though.

Dear all, I think to use freshly prepared salts is more advised for accurate study. Their preparation is quiet simple. This is much more stresses knowing the fair stability of these compound. Commercial products generally starts to decompose before use, purification should be done before use, which means an additional workup step is to be done. So, even when using commercial ones, time is Lost while shipping and purifying the products. My Regards

Hello Araf Shafqat, i have some issues regarding my D-Shaped PCF?

I can't get the fundamental fiber guided mode and plasmonic mode results.....

please help me...... will i show you my design?

You can find information on an experimental setup for aluminium SPR with nanostructure fabricated via EBL in a recent study by Feifei Zhang et al.

The fabricated Al nanodisks had diameters ranging from 70 to 160 nm, with a height of 50 nm. The pitch was 2.5 times the diameter.

Noble metals are prefered for plasmonics, since they do not for an oxide layer easily. Since the oxide layer dampens the plasmon resonance, experimental realisation of plasmonic behaviour in aluminium is tricky.

However, there has been some promising research done.

https://www.researchgate.net/publication/256497070_Localized_surface_plasmon_resonances_in_the_ultraviolet_from_large_scale_nanostructured_aluminum_films?

https://www.researchgate.net/publication/329455797_Long-term_stability_of_plasmonic_resonances_sustained_by_evaporated_aluminum_nanostructures?

I'd also get confused about these two concepts once. Sadly no answer helped - wikipedia, quora and researchgate or many papers/books given. They tended to be full of a loose combination of random terminologies.

Finally I understood once I found a review paper: 'Surface plasmon resonance in gold nanoparticles: a review', Figure 2 is very helpful (I guess you just want to understand the difference in a figurative rather than fully precise or mathematical way.)

SPR is surely a more generic term and can be divided into propogating SPR (occuring on a bulk metal surface) and localised SPR (occuring on a metal nanoparticle surface). Now the key points are the difference between 'propogating' and localised' and why. Localised SPR literally means the phenomenon is limited in space, because very importantly, the nanoparticle is so small that is even much smaller than the wavelength of visible light. So the free electron gas density can only dance (or oscillate, why? please think with the explanation below) collectively as a whole on that particle surface, and resonate with the part of the light wave with the right frequency.

By contrast, for bulk metals, (ideally) when the light wave is moving parallel to the plane of the metal-air (for example) interface, propagating SPR occurs on the surface which is very large in dimensions. This results in regionally and moving resonance of the free electron gas density along the propogating direction of the light wave. To further understand this, it is important to recall that light is in nature alternating, propogating magnetic and electric fields. The electric field therefore indicates alternatingly positive and negative potentials along the propogating dimension just above the metal surface, consequently inducing alternatingly negative and positive potentials on the metal surface. These regularly ever-changing induced potential differences then leads to back-and-forth movement of the free electron gas density, which is namely oscillation and with the right frequency, resonance. And because the light is propogating, so the regional motion has also to propogate along.

So that you can see, as an interesting consequence just because of the differences in the dimensions of the interface, localised SPR is transverse whereas propogating SPR is longitudinal, with respect to the light wave.

Hope this explains clearly.

Thank you Jonathan Shilantha Weerakkody for sharing your expertise on the fabrication of SPR-based devices, especially regarding that pesky adhesion layer! A major challenge (i.e. hot topic for research) is to have a mechanically stable adhesion layer which does not deteriorate the plasmons at the interface.

If you are in the linear optical regime, then the spectral response of the photonic structure is independent of the incident wavelength. The spectral response is the wavelength dependent transmission/reflection,.... of the structure. wavelength-dependent.

Thanks for sharing the experimences！

The answer is simple, as the other responses have explained, the SPR, in the case of nanoparticles the localized SPR, produces a strong enhancement of the electric field on the nanoparticles surface. The Raman effect is a nonlinear effect which strongly depends on the electric field strength, therefore if the material being analyzed is attached to the NP surface, the Raman effect is greatly enhanced, hence SERS. And yes, using a spelling corrector is a good idea...

Hadeer H. Abdelaziz Mie theory is already mentioned above. See also:

'The life of Gustav Mie and the development of the Lorenz-Mie solution to Maxwell's equations'

[Registration needed]

Mie dealt with the color of gold sols in relation to their size and the wavelength of impinging radiation

Aleksey Mikhailovich Polubotko I don't quite understand your comment. To whom does it refer?

doi:10.3390/polym10020123

AgNPs in an aqueous environment are oxidized in the presence of oxygen and protons, releasing Ag+ ions as the particle surface dissolves

@Rm Mal it has been recommended to keep the Rmax around 100-150 for reliable kD if the evaluation software is being used. However, the minimum Rmax I am not sure about but I think the noise level is around 2 RU when in running buffer - and may vary depending on buffer type..

Anyway, 15 Rmax has been reported before and see no reason why 10 RU should be reliable.. Of course the higher the better as long as there is no mass transport and the signal to noise ratio is reasonable to get a signal to fit the data..

Question : Can't you immobilise the analyte and use the ligand as "analyte" if the ligand has a bigger mass to increase the RU...?

By the way to get a realistic KD try 10 times less and 10 times more than the KD for the analyte concentrations for the binding..

Respected Durrani

Thank you for sharing the link.

Regards

N Das

In my impression, the major advantage of BLI is easy-to-use and a little bit higher throughput. As to the sensitivity, we have determined the binding kinetics of 124Da pyrazinoic acid on the pyrazinamide-target protein, PanD.

Sun Q, Li X, Perez LM, Shi W, Zhang Y, Sacchettini JC. The molecular basis of pyrazinamide activity on Mycobacterium tuberculosis PanD. Nat Commun. 2020 Jan;11(1):339 <doi:10.1038/s41467-019-14238-3>

I also made an R package to implement our data analysis routine. It's in the CRAN repository, and free to download and run on your dataset now.

Sun Q, Li X, Sacchettini JC (2020). smoke: Small Molecule Octet/BLI Kinetics Experiment. R package version 2.0.0. https://CRAN.R-project.org/package=smoke

Hello Oleh Yermakov , Thanks for your answer.

I have some questions.

I study SPR structures for depositing metal on optical fiber surfaces, which can be seen as Kretschmann configurations?

If so, in the SPR structure using optical fiber, if the thickness of the fiber becomes thick, can it be interpreted to mean that the ratio of Dip is reduced?