Luís D Carlos

Luís D Carlos
University of Aveiro | UA · Department of Physics

Ph.D,
Optical Materials and luminescent nanothermometers

About

697
Publications
82,730
Reads
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Introduction
Luís Carlos is a Full Professor at the Department of Physics, University of Aveiro, Portugal, and a correspondent member of the Lisbon Academy of Sciences (Physics) and Brazilian Academy of Sciences (Chemistry).
Additional affiliations
February 2012 - March 2012
São Paulo State University
Position
  • Visiting Professor
January 2008 - February 2008
French National Centre for Scientific Research
Position
  • Visiting Professor
February 1995 - present
University of Aveiro
Position
  • Professor (Full)
Education
December 1982 - June 1987
University of Coimbra
Field of study
  • Physics

Publications

Publications (697)
Article
The application of nanoparticles in the biological context generally requires their dispersion in aqueous media. In this sense, luminescent nanoparticles are an excellent choice for minimally invasive imaging and local temperature sensing (nanothermometry). For these applications, nanoparticles must operate in the physiological temperature range (2...
Article
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Thermal resolution (also referred to as temperature uncertainty) establishes the minimum discernible temperature change sensed by luminescent thermometers and is a key figure of merit to rank them. Much has been done to minimize its value via probe optimization and correction of readout artifacts, but little effort was put into a better exploitatio...
Article
Remote sensing through ratiometric luminescence thermometry based on trivalent lanthanide ions (Ln(III)) has lately become a promising technique due to its numerous applications. Most available Ln(III)‐based luminescent thermometers require a calibration process with a reference thermal probe (secondary thermometers) and recurrent calibrations are...
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Mimicking memory processes, including encoding, storing, and retrieving information, is critical for neuromorphic computing and artificial intelligence. Synaptic behavior simulations through electronic, magnetic, or photonic devices based on metal oxides, 2D materials, molecular complex and phase change materials, represent important strategies for...
Article
Optical Sensors The coupling of optical sensors to smartphones appears as a strategy for the new generation of mobile optical sensing and the Internet of Things (IoT). Healthcare services standout and the concepts of eHealth and mHealth emerge, being more and more explored towards the development of effective low‐cost and sustainable systems that p...
Article
Sustainable QR Codes In article number 2100227, Sidney J. L. Ribeiro, Luís D. Carlos, and co‐workers demonstrate how to design sustainable QR codes by combining recycled plastic and upconverting nanoparticles. The photothermal response of the QR codes under distinct laser irradiation power densities induces color‐tuning and temperature sensing, whi...
Article
The 1 : 1 : 1 reaction of YbCl3·6H2O, K3[Co(CN)6] and bpyO2 in H2O has provided access to a complex with formula [YbCo(CN)6(bpyO2)2(H2O)3]·4H2O (1) in a very good yield while its structure has been determined by single-crystal X-ray crystallography and characterised based on elemental analyses and IR spectra. Magnetic susceptibility studies showed...
Article
The growing demand aiming non-invasive diagnosis techniques applications has become an emerging field for developing more efficient bioprobes working in the near infrared (NIR) biological windows. In this work, we propose Er³⁺/Yb³⁺ co-doped yttrium niobate as a multifunctional material synthesized via sol-gel method. We study its NIR emission under...
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Smart designed core-shell nanostructures formed by a YVO4: Nd3+ nanoparticle as the core, the sonosensitizer hematoporphyrinmonomethyl ether as the carrier, and MnO2 nanosheets as the shell demonstrate bimodal imaging and highly efficient sonodynamic therapy of orthotopic gliomas.
Article
The Tb³⁺ ⁷F5 level has been shown to play an important role in the energy transfer involving this ion. This is due to the unusually long lifetime of this level which is commonly overlooked when treating energy transfer involving this ion. In this work, we give a rationalized explanation for this phenomenon. It is discussed that the ⁷F5 level is fed...
Article
We report the synthesis, structures, magnetic and luminescent properties of a series of three-blade propeller homoleptic lanthanide complexes [LnL3](ClO4)3·H2O·2MeCN (Ln = Eu (1), Tb (2), Dy (3), Er (4), Yb...
Article
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The luminescent solar concentrator (LSC) concept appeared almost forty years ago, as a solution to overcome the limitations related to photovoltaic cell efficiency. Nowadays, they are seen as a promising approach to integrate photovoltaic elements into the built environment, in an invisible way and without detrimental effects to the aesthetics of t...
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This study investigates how rare earth ion (RE³⁺) concentration affects stabilization of the crystalline structure and infrared-to-visible upconversion (UC) in Er³⁺/Yb³⁺ co-doped yttrium tantalates, synthesized by the sol–gel method. Under 980 nm, the samples exhibited intense UC luminescence. The crystalline phases strongly influenced the emission...
Article
The miniaturization of the silicon chips is reaching its physical limits, and the transistors are so small that current leakage will become an insurmountable problem. Additionally, the actual chip shortage makes clear the excessive world dependence on silicon, stressing the need for silicon‐free computing strategies. Quantum computing process infor...
Article
Shell Passivation Effect The effectiveness of shell passivation in alleviating the surface quenching in Ln3+‐doped luminescent nanocrystals has long been approved, yet the understanding of passivation mechanisms remains elusive. In article number 2100194, Rui Shi, Carlos D. S. Brites, and Luís D. Carlos review the context of debates on this topic a...
Chapter
Sensors play a key role on the Internet of Things (IoT) providing monitoring inside and outside the communication networks in a multitude of parameters. Challenges towards IoT lie in the lack of affordable strategies able to convert sustainably a signal from an optical sensors network into a digital data sequence. The coupling of optical sensors to...
Article
Surface quenching is the main reason limiting the luminescence performance of Ln³⁺-doped nanocrystals and their practical applications. Although the shell passivation strategy effectively improves the luminescence efficiency, the understanding of the relevant passivation mechanisms remains elusive and contradictory explanations are often proposed....
Chapter
The role of the energy transfer mechanisms behind the efficient emission of lanthanide-based complexes will be discussed. Emphasis will be given to the quantification of such energy transfer mechanisms to enable the rational design of lanthanide-based complexes (namely, β-diketones) for advanced photonic applications such as luminescent solar conce...
Article
Simultaneous fine-tune of magnetic and optical properties in lanthanide single-molecule magnets (SMMs) is a daunting task. Even more so when additional functionalities, like luminescence thermometry, are sought after. Herein, we...
Article
The synthesis of dual-emission nanocomposite materials has emerged as an excellent strategy for designing new and advanced luminescent ratiometric thermometers. In the present work, a dual-emission nanocomposite material based on...
Article
Luminescence thermometry allows the remote monitoring of the temperature and holds the promise to drive the next generation of future nano or micrometric devices. Materials able to sense the temperature are usually based on one or several lanthanide ions allowing a ratiometric measurement. Optimizing the thermometric features is usually achieved th...
Article
Full-text available
Quick-response (QR) codes are gaining much consideration in recent years due to their simple and fast readability compared with conventional barcodes. QR codes provide increased storage capacity and safer access to information, fostering the development of optical or printed smart tags as preferred tools for the Internet of Things (IoT). Herein, th...
Article
We combined the sensing capabilities of Er³⁺-doped upconverting nanoparticles (UCNPs) with hyperspectral microscopy to construct thermal images on thermally active nanostructures. Here, we studied the heat dissipation of a percolating network of silver nanowires under controlled electric current flow. We quantified the electrothermal action by anal...
Article
The hexagonal-phase (β) of NaREF4 upconversion nanocrystals (RE = rare earth elements) has been widely employed because of the outstanding luminescence performance, yet less is known about the essence of this superior property. The current understanding of this issue is raised from the advantage of weak electron-vibration interactions in fluoride s...
Article
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The need to sense and track in real time through sustainable and multifunctional labels is exacerbated by the COVID‐19 pandemic, where the simultaneous measurement of body temperature and the fast tracking of people is required. One of the big challenges is to develop effective low‐cost systems that can promote healthcare provision everywhere and f...
Article
Luminescence Nanothermometry Selecting green fluorescent protein and Ag2S nanocrystals as illustrative multiparametric thermographic phosphors, in article number 2100301, Luís D. Carlos and co-workers demonstrate that the synergy between multiparametric readouts and multiple linear regression makes possible a 10-fold improvement in the performance...
Article
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In this work we demonstrate that large temperature sensitivity over a wider temperature range is possible by adopting the dual use of Raman and photoluminescence (PL) signals emitted by rare-earth doped crystalline phosphors. We define Raman-PL-intensity ratio (RPIR) as an alternative thermometric parameter to define temperature sensitivity and exp...
Article
Hyperspectral microscopy is an intriguing technique combining spectroscopy with optical microscopy that can be used to simultaneously obtain spectral and spatial information. The relevance of hyperspectral imaging in biomedical applications such as the monitoring of bioimaging agents, the identification of pathogens and cancerous cells, and the cel...
Article
Using luminescent materials for temperature measuring is considered the perspective remote technique nowadays. Designing new materials which combine a wide operating range with satisfying relative thermal sensitivity (Sr) and temperature uncertainty values is still a challenge. In this paper, we study the luminescence properties and thermometric pe...
Article
Full-text available
New luminescent cage-like tetranuclear silsesquioxanes [NEt4][(Ph4Si4O8)2(Tb3Eu)(NO3)4(OH)(EtOH)3(H2O)]·4(EtOH) (1) and [NEt4]2[(Ph4Si4O8)2(Tb2Eu2)(NO3)6(EtOH)2(MeCN)2]·4(MeCN) (2) present a tunable thermosensitive Tb3+-to-Eu3+ energy transfer driven by Tb3+ and Eu3+ emission and may be used as temperature sensors operating in the range 41-100 °C w...
Article
Sensors are increasingly present in the everyday life in widespread technological applications, and engineering smart systems able to simultaneously detect different physical quantities represents a scientific challenge. Taking advantage of the molecular chemistry realm that offers the possibility to finely adjust physical properties, it is demonst...
Article
Photon upconversion taking place in small rare-earth-doped nanoparticles has been recently observed to be thermally modulated in an anomalous manner, showing thermal enhancement of the emission intensity. This effect was proved to be linked to the role of adsorbed water molecules as surface quenchers. The surface capping of the particles has a dire...
Article
White light-emitting diodes (WLEDs) revolutionized the lighting industry providing high energy efficiency and a long lifetime. The recent development of efficient ultraviolet (UV) LEDs pushed forward the development of WLEDs based on mixtures of down-shifting phosphors and the current challenges are focused on the design of sustainable light conver...
Article
Luminescent spherical, redispersable, and monodisperse Er³⁺,Yb³⁺ co-doped Y2O3 nanoparticles were synthesized by homogenous precipitation followed by thermal annealing. Cubic Y2O3 nanoparticles exhibited high colloidal stability in water and biological medium and 90% cell viability toward glioblastoma multiforme cell lines. Confocal microscopy reve...
Article
Luminescence thermometry has substantially progressed in the last decade, rapidly approaching the performance of concurrent technologies. Performance is usually assessed through the relative thermal sensitivity, Sr, and temperature uncertainty, δT. Until now, the state‐of‐the‐art values at ambient conditions do not exceed maximum Sr of 12.5% K−1 an...
Article
JOYSpectra is a free-of-charge web platform for perform online calculations of spectroscopic properties of lanthanide-based compounds and materials. It has several features and functionalities to provide a detailed analysis of the intensity parameters. For instance, their dependence on the chemical environment of the lanthanide ion (Ln³⁺) such as s...
Article
The Front Cover shows a representative structure of the series of new tetranuclear Dy3+ based cage‐like silsesquioxanes that were synthesized and investigated. All of them present the characteristic green‐yellow Dy3+ emission. In addition, the Dy3+/Y3+ cage exhibits field‐induced Single Molecule Magnetic (SMM) behavior, which makes it the first mul...
Article
We report here the synthesis, structure, luminescence and magnetic properties of three new cage‐like tetranuclear silsesquioxanes (Et 4 N) 2 [(PhSiO 1..5 ) 8 (Y 0.75 Dy 0.25 O 1.5 ) 4 (O)(NO 2.5 ) 6 (EtOH) 2 (MeCN) 2 ] and (Cat) 2 [(PhSiO 1.5 ) 8 (DyO 1.5 ) 4 (O)(NO 2.5 ) 6 (EtOH) 2 (MeCN) 2 ] (Cat = Et 4 N or Ph 4 P). They present a characteristic...
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Full-text available
Sensors play a key role on the Internet of Things (IoT), providing monitoring inside and outside the networks in a multitude of parameters. A fundamental parameter to sense is temperature, being essential to acquire knowledge on the best way to include thermal sensing into the communications networks. Despite that the temperature measurement in the...
Article
The temperature determination using luminescent materials is nowadays considered the perspective remote technique for temperature gauging, despite the few examples reported so far combining wide operating temperature range with satisfying relative thermal sensitivity and temperature uncertainty values. In this paper, we study the Y3(Al,Ga)5O12:0.1%...
Article
Full-text available
Photonic materials featuring simultaneous iridescence and light emission are an attractive alternative for designing novel optical devices. The luminescence study of a new optical material that integrates light emission and iridescence through liquid crystal self-assembly of cellulose nanocrystal-template silica approach is herein presented. These...
Article
An alternative approach to classical surface plasmon resonance spectroscopy is dielectric-loaded waveguide (DLWG) spectroscopy, widely used in the past decades to investigate bio-interaction kinetics. Despite their wide application, a successful and clear approach to use the DLWGs for the one-step simultaneous determination of both the thickness an...
Article
Full-text available
The potential applications in disparate fields led to a rapid evolution of luminescence thermometry. In particular, luminescent thermometry based on trivalent lanthanide ions (Ln³⁺) has become very popular in the past decade due to the unique versatility, stability, and narrow emission band profiles covering a broad spectral range (from ultraviolet...
Article
This work presents a theoretical study on the geometries and intramolecular energy transfer (IET) process of Tb3+‐complexes based on the Ruhemman's purple (RP) as ligands. Density functional theory and its time‐dependent extension are performed to examine the coordination energies and excited states using the ωB97X‐D3/MWB54/def2‐TZVP/polarizable co...
Article
In the last decade, numerous Ln‐bearing metal‐organic frameworks (MOFs) have been reported for luminescence thermometry applications. Although the Ln³⁺ composition is always thoroughly determined, this parameter is never optimized to improve thermometric performances. Here, the optimization of thermometric performances of luminescent probes is tack...
Article
Seven-coordinate, pentagonal-bipyramidal (PBP) complexes [Ln(bbpen)Cl] and [Ln(bbppn)Cl], in which Ln = Tb3+ (products I and II), Eu3+ (III and IV), and Gd3+ (V and VI), with bbpen2- = N,N'-bis(2-oxidobenzyl)-N,N'-bis(pyridin-2-ylmethyl)ethylenediamine and bbppn2- = N,N'-bis(2-oxidobenzyl)-N,N'-bis(pyridin-2-ylmethyl)-1,2-propanediamine, were synth...
Article
Luminescence (nano)thermometry is an emerging and promising field for remote temperature sensing and thermal imaging of both the surface and interior of objects. While the field is dominated by trivalent...
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Full-text available
Luminescence thermometers and manometers are among the most paramount emerging applications of phosphors nowadays, and remote reading is not the only attractive advantage they offer. Presently, truly encouraging examples offering both a wide operating range and appreciating thermal sensitivity are still limited. Double-mode sensors are especially a...
Article
The growing interest in the use of luminescence thermometry for noncontact temperature reading under very specific conditions imposes the need to develop an approach allowing modification of the luminescence parameters of a thermometer accordingly to requirements. Therefore, in response to these expectations, this manuscript reports an approach to...
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Commercial light‐emitting diodes are a low‐cost and energy‐efficient solution for the implementation of optical wireless communication, known as visible light communication (VLC). This technology has a huge growing interest, being recently a research spotlight in the scientific community, especially due to the increasing popularity and rapid develo...
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The emergence of luminescence nanothermometry in bio and nanomedicine has enabled achievements outside the reach of conventional techniques. For instance, it has provided real‐time monitoring of in vivo thermal therapies of tumors, a mandatory requirement for these techniques to work safely and efficiently. However, the reliability of intratumoral...
Article
Heat transfer and thermal properties at the nanoscale can be challenging to obtain experimentally. These are potentially relevant for understanding thermoregulation in cells. Experimental data from the transient heating regime in conjunction with a model based on the energy conservation enable the determination of the specific heat capacities for a...
Article
Luminescence thermal stability is a major figure of merit of lanthanide-doped nanoparticles playing an essential role in determining their potential applications in advanced optics. Unfortunately, considering the intensification of multiple electron-vibration interactions as temperature increases, luminescence thermal quenching of lanthanide-doped...
Article
Lanthanide-doped nanoparticles (LnNPs) are versatile near-infrared (NIR) emitting nanoprobes with growing interest for biomedicine-related imaging. In the race towards the brightest LnNPs, high photoluminescence quantum yield (PLQY) values are attained by implementing core/shell engineering, particularly with an optically inert shell. In this work,...
Article
The experimental determination of the velocity of a colloidal nanoparticle (v_NP) has recently became a hot topic. The thermal dependence of v_NP is still left to be explored although it is a valuable source of information allowing, for instance, to distinguish between ballistic and diffusive regimes. Optical tweezers (OTs) constitute a tool especi...
Article
Flexible coatings with dual capabilities for remote real-time temperature sensing and photothermal conversion have a huge potential in the field of advanced thermal actuated optoelectronic applications. In this work, we demonstrated that plastic free-standing films of intriguing upconversion high absolute emission quantum yield (~0.1452, excited at...
Article
Trivalent lanthanide ions (Ln3+) are used to prepare a plethora of coordination compounds; metal-organic frameworks (MOFs) being amongst the most sought-after in recent years. The porosity of Ln-MOFs is often complemented by the luminescence imparted by the metal centers, making them attractive multifunctional materials. Here, we report a class of...
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In the present work, new Tb³⁺/Eu³⁺tetrakis (benzoyltrifluoroacetone) complexes containing imidazolic counterions were successfully prepared and characterized via elemental analysis, infrared spectroscopy, thermogravimetry, and X-ray powder diffraction. Photophysical features of the Eu³⁺ ion, such as the intrinsic emission quantum yields, radiative...
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Despite the current maturity and reliability of white‐light‐emitting diodes (WLEDs), the control of the correlated color temperature (CCT) is still a challenge, arising from the lack of the red color which is often associated with dysregulations of the human circadian rhythm. Warm WLED prototypes were fabricated coating UV‐LEDs with yellow‐ and blu...
Article
Measurement of thermogenesis in individual cells is a remarkable challenge due to the complexity of the biochemical environment (such as pH and ionic strength) and to the rapid and yet not well-understood heat transfer mechanisms throughout the cell. Here, we present a unique system for intracellular temperature mapping in a fluorescence microscope...
Article
Liquid water, despite its simple molecular structure, remains one of the most fascinating and complex substances. Most notably, many questions continue to exist regarding phase transitions and anomalous properties of water, which are subtle to observe experimentally. Here, we report a sharp transition in water at 330 K unveiled through experimental...
Article
Nanothermometry is the study of temperature at the submicron scale with a broad range of potential applications such as cellular studies or electronics. Molecular luminescent based nanothermometers offer a non‐contact means to record these temperatures with high spatial resolution and thermal sensitivity. A luminescent based molecular thermometer c...
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The mononuclear complex [Yb(H3L1,1,4)]•2MeOH (1•2MeOH), with a new heptadentate N4O3 ligand, was isolated and structurally characterised. The opto magnetic properties of 1•2MeOH were investigated, showing that this complex is a bifunctional compound. Accordingly, 1•2MeOH reveals two coexisting functionalities: field-induced single molecule magnet b...