Guillermo Orellana

Complutense University of Madrid | UCM · Department of Organic Chemistry I

Water conductivity sensing relies universally on electrical measurements, which are subject to corrosion of the electrodes and subsequent signal drift in prolonged in situ uses. Furthermore, they cannot provide contactless sensing or remote readout. To this end, a novel device for water conductivity monitoring has been developed by employing a micr...

Antimony (Sb) is currently a widespread element with key roles in telecommunication, sustainable energy, and military industries, among others. Its significant toxicity determines the need to realize sensors for water, air, and soil and the industrial process monitoring of Sb species. Unfortunately, no antimony sensors exist so far, and just labora...

Progress in synthetic biology and nanotechnology plays at present a major role in the fabrication of sophisticated and miniaturized analytical devices that provide the means to tackle the need for new tools and methods for environmental and food safety. Significant research efforts have led to biosensing experiments experiencing a remarkable growth...

Cyclic olefin copolymers (COC; e.g., Zeonor, Topas, Arton, etc.) are materials with outstanding properties for developing point-of-care systems; however, the lack of functional groups in their native form makes their application challenging. This work evaluates different strategies to functionalize commercially available Zeonor substrates, includin...

Galactose Oxidase (GalOx) has gained significant interest in biocatalysis due to its ability for selective oxidation beyond the natural oxidation of galactose, enabling the production of valuable derivatives. However, the practical application of GalOx has been hindered by the limited availability of active and stable biocatalysts, as well as the i...

This work reports the optimization of a method using Molecularly Imprinted Polymers (MIPs) for the simultaneous determination of zearalenone and alternariol mycotoxins. The method was optimized using a chemometric approach where in the optimized conditions, the cartridges with a mixture (50:50, w/w) of both MIPs, were loaded with 30 mL of sample, w...

Pulmonary surfactant (PS) has been proposed as an efficient drug delivery vehicle for inhaled therapies. Its ability to adsorb and spread interfacially and transport different drugs associated with it has been studied mainly by different surface balance designs, typically interconnecting various compartments by interfacial paper bridges, mimicking...

Photodynamic therapy (PDT), a combination of light, molecular oxygen and a photosensitizing dye, has gained attention as a promising technique to treat various types of cancers. Among all the photosensitizers reported so far, ruthenium(II) polypyridyl complexes exhibit unique photophysical and photobiological features owing to their photostability,...

One of the major difficulties in the development of evanescent wave optical fiber sensors (EWOFS) lies in the complexity of the manufacturing of the chemosensitive element, particularly when using plastic optical fibers (POFs). While these fibers are appealing waveguides thanks to their low cost, ease of connectorization and robustness, the need fo...

This chapter outlines the contribution of luminescent techniques (fluorescence and phosphorescence) to monitor the quality of waters. An initial section summarizes the principles and features of luminescence, the determination of intrinsically fluorescent analytes vs. indicator-based sensors, the photochemical quenching of electronic excited states...

The present paper describes a compact point of care (POC) optical device for therapeutic drug monitoring (TDM). The core of the device is a disposable plastic chip where an immunoassay for the determination of immunosuppressants takes place. The chip is designed in order to have ten parallel microchannels allowing the simultaneous detection of more...

A family of ruthenium(II) complexes containing one 2,2′-biimidazole (bim) ligand and two polypyridyl (NN) ligands has been prepared and their photophysical and photochemical features have been tested in the presence of tenuazonic acid (TeA), a widespread food and feed mycotoxin of current concern. While not tested in in vivo studies, TeA and other...

Loading of photosensitizing dyes into polymer beads is a meaningful strategy to improve their performance in photodynamic therapies (PDTs) or in sensing applications. In this work we describe a straightforward method for doping 390 nm and 26 nm carboxylated polystyrene nanoparticles with the hydrophobic tris(4,7-diphenyl-1,10-phenanthroline)rutheni...

Formaldehyde (FA) involvement in specific economic activities has become one of the major threats for their worker’s health. The risks of exposure to FA include carcinogenic effects and important respiratory affections. One of the essential requirements to ensure safe working conditions is the availability of reliable FA monitoring systems. In this...

Tenuazonic acid ((5S)-3-acetyl-5-[(2S)-butan-2-yl]-4-hydroxy-2,5-dihydro-1H-pyrrol-2-one, TeA) is a widespread Alternaria fungi mycotoxin in food produce. This toxin may be allergenic and provoke hay fever and asthma. Therefore, rapid methods to selectively detect TeA are needed. With this aim, we have engineered a novel trifunctional (red-luminesc...

Objectives Therapeutic drug monitoring (TDM) plays a crucial role in personalized medicine. It helps clinicians to tailor drug dosage for optimized therapy through understanding the underlying complex pharmacokinetics and pharmacodynamics. Conventional, non-continuous TDM fails to provide real-time information, which is particularly important for t...

This work explores the potential for strategizing pulmonary surfactant (PS) for drug delivery over the respiratory air-liquid interface: the interfacial delivery. The efficacy of PS- and interface-assisted drug vehiculization was determined both in vitro and in vivo using a native purified porcine PS combined with the hydrophobic anti-inflammatory...

Tenuazonic acid (TeA) is a common mycotoxin produced by Alternaria species found in various foodstuffs. Herein, we describe the preparation of porous molecularly imprinted polymer (MIP) microspheres doped with Eu(III), for selective fast analysis of TeA in rice extracts. The TeA template, bearing a β-diketone moiety, is a good Eu(III)-chelating ant...

Formaldehyde is an indoor air pollutant that is widespread across many industries. The established implication of formaldehyde in respiratory conditions and its carcinogenicity pose a risk to millions of workers in the wood and textile industries. We have developed an optical sensor based on the evanescent wave absorption of light by the tailored f...

Two new highly water-soluble amphiphilic Ru(II) polypyridyl complexes containing N-1,10-phenanthrolin-5-yldocosanamide and either 1,10-phenanthroline (phen, 1) or 1,4,5,8-tetraazaphenan-threne (TAP, 2) as ligands were synthesised and their photophysical and photobiological properties evaluated. Both complexes showed a rapid cellular uptake and disp...

Ammonia monitoring in the gas phase is essential in those activities (e.g. fertilizers, biogas and biomethane production; landfills of waste; intensive livestock farming; industrial refrigeration systems; automotive sector) where the high concentration of this gas can pose a risk to the human health and the environment. Each of the current sensing...

Aeronautical industry deals with extremely complex and sensitive issues, the most critical of which being arguably aircraft safety during flight. For a variety of reasons and through different pathways, the integrity of an airplane might be compromised in such a way that passengers and crew might be at risk. In the case of military aircraft, this r...

Reliable robust sensor systems are essential to monitor in situ and allow controlling of the evolution of bioprocesses in order to maximize the product yields and guarantee their quality. The more chemical and biological information is collected, the better strategies can be applied to generate highly productive cell lines and successfully determin...

Hydrogen sulfide monitoring has become essential in the natural gas industry, biogas production, waste water treatment plants, paper mills, sewers and landfills of waste due to its toxic, irritating, extremely flammable and corrosive features. However, each of the current monitoring technologies (gas chromatography, lead acetate tape, electrochemic...

Homogeneous immunoassays represent an attractive alternative to traditional heterogeneous assays due to their simplicity, sensitivity, and speed. On the basis of a previously identified epitope-mimicking peptide, or mimotope, for fumonisin B1 (FB1) mycotoxin, we have developed a homogeneous fluorescence quenching immunoassay based on (17.1 ± 2.0)-n...

Fluorescent polarity probes are usually based on intramolecular charge transfer excited states of selected dyes, the behavior of which in different solvents is traditionally rationalized by the well-known Lippert-Mataga treatment of the “general solvents effect”. Less often transition metal coordination complexes are used as luminescent probes, eve...

Biomethane is a sustainable biofuel composed of methane and minor components such as CO2, O2 or H2S. The presence of O2 can be deleterious for the integrity of the pipelines and gas storage systems, as it causes corrosion and may involve explosions. Therefore, O2 monitoring in biomethane has become mandatory. European Standard EN16723 establishes m...

In this article, we describe a fluorescence polarization immunoassay (FPIA) using a new label - near-infrared fluorescent dye. The developed FPIA method was optimized for the rapid analysis of free mycophenolic acid (MPA) in plasma of transplanted patients. The approach is based on the fluorescence competitive assay between the target immunosuppres...

Temperature is a key parameter in many fields and luminescence-based temperature sensing is a solution for those applications in which traditional (mechanical, electrical, or IR-based) thermometers struggle. Amongst the indicator dyes for luminescence thermometry, Ru(II) polyazaheteroaromatic complexes are an appealing option to profit from the wid...

Fluorescence immunoassays are popular for achieving high sensitivity, but they display limitations in biological samples due to strong absorption of light, background fluorescence from matrix components, or light scattering by the biomacromolecules. A powerful strategy to overcome these problems is introduced here by using fluorescent magnetic nano...

Molecularly imprinted porous polymer microspheres selective to Alternaria mycotoxins, alternariol (AOH) and alternariol monomethyl ether (AME), were synthesized and applied to the extraction of both mycotoxins in food samples. The polymer was prepared using 4-vinylpiridine (VIPY) and methacrylamide (MAM) as functional monomers, ethylene glycol dime...

A 2,3-diaminophenazine bis-urea fluorescent probe monomer (1) was developed. 1 responds to phenylphosphate and phosphorylated amino acids in a ratiometric fashion with en-hanced fluorescence accompanied by the development of a red-shifted emission band arising from an excited-state proton transfer (ESPT) process in the hydrogen bonded probe-analyte...

This paper describes the preparation of silica nanoparticles doped with a molecularly engineered luminescent Ru(II) complex for the selective determination of Cu(II) ions in aqueous media. Initially, three novel indicator dyes, namely [Ru(phen)2(L)]²⁺, where L is either hmpi (2-(1H-imidazo[4,5-f]-1,10-phenanthrolin-2-yl)-4-methoxyphenol), haip (1-(...

Pulmonary surfactant is a crucial system to stabilize the respiratory air-liquid interface. Furthermore, pulmonary surfactant has been proposed as an effective method for targeting drugs to the lungs. However, few studies have examined in detail the mechanisms of incorporation of drugs into surfactant, the impact of the presence of drugs on pulmona...

Pyrene-labeled acrylamide monomers. synthesis and spectroscopic characterization of four acrylamide/methacrylamide monomers containing N-(pyren-1-yl) or N-(pyren-1-methyl) moieties as fluorescent labels. These monomers have been designed to exploit the well-known properties of pyrene as a molecular probe of the polarity of its immediate environmen...

UV to green light-emitting diodes (LEDs) based on III-nitride semiconductors have revolutionized areas as diverse as illumination, medical treatments and biophotonics. Chemical sensing also benefited, as many fluorophores that provide extreme sensitivity and selectivity absorb light in that region. Additionally, integration and smartphone-based sen...

The work presented in this paper offers a robust, effective and economically competitive method for online detection and monitoring of the presence of molecular hydrogen in the heat transfer fluids of parabolic trough collector plants. The novel method is based on a specific fluorescent sensor according to the ES2425002 patent (“Method for the dete...

A novel therapeutic drug monitoring point of care testing (POCT) optical device for the detection of immunosuppressants in transplanted patients was designed and tested, with the body interface constituted by an intravascular microdialysis catheter (MicroEye®) which provides the dialysate as clinical sample. An optical biochip with 10 microchannels...

Nuestro equipo investigador, en colaboración con la empresa Grupo Interlab, S.A. (Madrid), lleva varios años involucrado en un ambicioso proyecto que ha llevado al mercado un instrumento optoelectrónico para análisis y control medioambiental e industrial. El sistema multicanal utiliza sensores y biosensores sobre fibra óptica basados en indicadores...

This work reports the preparation of molecularly imprinted polymers (MIPs) selective to cephalosporin (CF) antibiotics, and their application as molecularly imprinted solid-phase extraction (MISPE) sorbents for the determination of these antimicrobials in milk samples. Several functional monomers and cross-linkers have been screened to select the b...

We have developed disposable color-changing polymeric films for quantification of furfural, —a freshness indicator—, in beer using a smartphone-based reader. The films are prepared by radical polymerization of 4-vinylaniline, as furfural-sensitive indicator monomer, 2-hydroxymethylmethacrylate as co-monomer and ethylene dimethylmethacrylate (EDMA)...

Molecularly imprinted porous polymer microspheres have been prepared for selective binding of alternariol (AOH), a phenolic mycotoxin produced by Alternaria fungi. In order to lead the synthesis of recognition materials, four original AOH surrogates have been designed, prepared and characterized. They bear different number of phenol groups in vario...

This work describes the development and application of class-selective molecularly imprinted polymers (MIPs) for the analysis of beta-lactamase-resistant penicillins, namely cloxacillin (CLOXA), oxacillin (OXA), and dicloxacillin (DICLOXA), in milk samples. Our method is based on molecularly imprinted solid-phase extraction (MISPE) coupled to high-...

Molecularly imprinted membrane of fluorescent nanofilaments with red emission for sensoring

An original CO2 analyser has been developed using just a phase-sensitive luminescent O2 sensor as transducer. The goal of this work is to provide a robust sensor for continuous monitoring of microalgae cultures in solar reactors for biomass production. At the pH of the culture medium (8−9), the microorganism carbon source is largely present as HCO3...

One of the main problems associated with the application of sensors for continuous monitoring in the (aqueous) environment is related to biofouling of the sensitive membranes.1 Silicone rubber is the material of choice in optical and electrochemical sensors for oxygen monitoring. This material provides excellent oxygen permeability (300-400 x 10^−1...

We have investigated the photophysical and photochemical features of a luminescent heteroleptic Ru(II) -polypyridyl probe and of its corresponding Ru(II) -Cu(II) dinuclear complex formed upon the analyte binding through extensive density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. The molecular probe contains the tailored...

The first demonstration of fabrication of submicron lateral resolution molecularly imprinted polymer (MIP) patterns by photoinduced local polymerization within metal subwavelength apertures is reported. The size of the photopolymerized MIP features is finely tuned by the dose of 532 nm radiation. Rhodamine 123 (R123) has been selected as a fluoresc...

Silicones are extremely versatile materials that have found manifold applications in optical sensing of chemical species. Their high gas permeability, processability, optical transparency, composition tunability, resiliency to biofilm adhesion and low cost, together with good chemical and thermal stability, have made silicones one of the polymer ma...

This work describes the design and synthesis of molecularly imprinted polymers (MIPs) for selective recognition of alternariol (AOH) and alternariol monomethyl ether (AME) (Figure 1). Both molecules are toxic metabolites of Alternaria fungi found in contaminated food such as cereal, nuts and tomatoes, in processed food like beer and wine, or in ani...

This work describes the design and synthesis of molecularly imprinted polymers (MIPs) for selective recognition of alternariol (AOH) and alternariol monomethyl ether (AME) (Figure 1). Both molecules are toxic metabolites of Alternaria fungi found in contaminated food such as cereal, nuts and tomatoes, in processed food like beer and wine, or in ani...

This work describes the design and synthesis of molecularly imprinted polymers (MIPs) for selective recognition of alternariol (AOH) and alternariol monomethyl ether (AME) (Figure 1). Both molecules are toxic metabolites of Alternaria fungi found in contaminated food such as cereal, nuts and tomatoes, in processed food like beer and wine, or in ani...

This work describes the design and synthesis of molecularly imprinted polymers (MIPs) for selective recognition of alternariol (AOH) and alternariol monomethyl ether (AME) in foodstuff using fluorescence techniques.

A strongly blue-fluorescent disulfonated pyrenedimethacrylamide has been synthesized and its spectroscopic features tested in the presence of diquat (DQ) and paraquat (PQ) herbicides in water. UV-vis absorption revealed the formation of a 1:1 complex between the probe and the “quats”, the strongest binding with DQ occurring in acetonitrile (K = 1.8...

Different photosensitizing materials manufactured by immobilizing (0.5-3.0 g m(-2)) tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(ii) (RDP(2+)), [C60]-fullerene, or 1-(4-methyl)-piperazinylfullerene (MPF) on porous neutral (pSil) or surface-modified anionic (pSil(-)) poly(dimethylsiloxane) are compared on the grounds of their singlet molecular ox...

The microalgal species Dictyosphaerium chlorelloides (D. c.) was immobilized into porous silicone films and their photosynthetic activity was monitored with an integrated robust luminescent O2 sensor. The biosensor specificity towards a particular pesticide has been achieved by manufacturing a fiber-optic dual-head device containing both analyte-se...

Alternariol and alternariol monomethyl ether are two of the toxins produced in greatest amounts by fungi of the family Alternaria. They occur frequently in foodstuffs and continued consumption thereof may have negative effects on human health and therefore it is important to develop effective detection methods that prevent the introduction of said...

The development and characterization of novel, molecularly imprinted polymer nanofilament-based optical sensors for the analysis of enrofloxacin, an antibiotic widely used for human and veterinary applications, is reported. The polymers were prepared by nanomolding in porous alumina by using enrofloxacin as the template. The antibiotic was covalent...

Red-luminescent 150-nm silica nanoparticles have been designed and prepared as a versatile platform for developing FRET (Förster Resonance Energy Transfer) biomimetic assays. Ru(phen)32+ dye molecules embedded off-center in the silica core provide the long-lived donor emission, and a near-infrared labeled analyte serves as fluorescent acceptor (the...

Alternariol and alternariol monomethyl ether are two of the toxins produced in greatest amounts by fungi of the family Alternaria. They occur frequently in foodstuffs and continued consumption thereof may have negative effects on human health and therefore it is important to develop effective detection methods that prevent the introduction of said...

Development of PCB-integrateable microsensors for monitoring chemical species is a goal in areas such as lab-on-a-chip analytical devices, diagnostics medicine and electronics for hand-held instruments where the device size is a major issue. Cellular phones have pervaded the world inhabitants and their usefulness has dramatically increased with the...

Mycotoxins small toxic chemical product formed as secondary metabolites by few fungal species that readily colonies crops and contaminates them with toxins in the field or after harvest. Mycotoxins it is come from Greek word fungus " mykes " and Latin word " toxicum " mean poison i. Alternaria is reported to be the most fungal species are capable t...

In this work, we develop a new technique for alternariol detection easy to use, highly sensitive and selective. This could be achieved by using optical sensor based on molecularly imprinted polymers (MIPs) selective for alternariol recognition.

Biomimetic assays with molecularly imprinted polymers (MIPs) are bound to be an alternative to the traditional immuno-analytical methods based on antibodies. This is due to the unique combination of advantages displayed by the artificial materials including the absence of animal inoculation and sacrifice, unnecessary hapten conjugation to a carrier...

This chapter provides a comprehensive guide to the current sensor devices for online monitoring of water-quality parameters and in situ analysis of the most common pollutants. Both physical and chemical sensing devices are reviewed. When available, biosensors (chemical sensors based on recognition materials of biological origin) are also considered...

This paper describes the synthesis and characterization of a fluorescent ion-imprinted polymer (IIP) for selective determination of copper ions in aqueous samples. The IIP has been prepared using a novel functional monomer, 4-[(E)-2-(4'-methyl-2,2'-bipyridin-4-yl)vinyl]phenyl methacrylate (abbreviated as BSOMe) that has been spectroscopically chara...

Two new methods for covalent functionalization of GaN based on plasma activation of its surface are presented. Both of them allow attachment of sulfonated luminescent ruthenium(II) indicator dyes to the p- and n-type semiconductor as well as to the surface of nonencapsulated chips of GaN light-emitting diodes (blue LEDs). X-ray photoelectron spectr...

We present the results of a chemical attack on the optical fiber surface previous to the deposition of the double layer (metal plus dielectric) in Double-layer uniform-waist tapered fibers (DLUWTs) used for the development of SPR sensors. It is shown how this simple chemical treatment increases the roughness of the surface and permits improvement o...