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The purpose of this study is to develop a non-enzymatic based glucose-sensing platform composed of Bodipy-BBV dual system which can be monitored by a photodetector under the blue LED excitation.

The sensor has been developed from a dual system including a fluorescent dye, an aldehyde derivative of boron dipyrromethene (Bodipy) and a quencher, orto-boronic acid linked viologen (o-BBV) where their combination resulted in a ratiometric fluorescence quenching in ethanol: PBS (1:1, pH:7.4) solution under UV light excitation. By glucose addition, o-BBV has been released from the Bodipy and binded to cis-diol groups of glucose, thereby fluorescence emission of Bodipy has been regained. Furthermore, a setup consisting of a light emitting diode (LED) and a photodiode (PD) was used to prove electrical detection of glucose without the need for expensive and bulky optical equipment, enabling the development of a miniaturized and low-cost glucose-sensing platform.

The fluorescence intensity of the Bodipy derivative in the solution (2 × 10⁻⁶ M) was diminished by 93% in the presence of o-BBV solution (5 × 10⁻³ M). Upon the glucose addition, 81% of the Bodipy fluorescence intensity has been recovered after introduction of 30 mM of glucose, where the ratio of o-BBV/Bodipy was 35:1. A linear response between 10 and 30 mM glucose concentration was obtained, which covers the biologically significant range. A high correlation between the photodiode current and Bodipy fluorescence intensity was achieved.

Even though Bodipy molecules are known with their superior optical properties and applied to the fluorescence-based detection of glucose, to the best of the authors’ knowledge, no work has been reported on Bodipy-BBV dual system to detect glucose molecules as a non-enzymatic based method. This design enables the dye and the quencher to independently coexist in the solution, allowing for tuning of their individual concentrations to optimize the glucose sensitivity. Furthermore, an electrical light detection scheme consisting of a LED and a photodiode has been implemented to eliminate the bulky optical equipment from the measurement setup and further this work for the development of a compact and inexpensive sensor. The results presented here demonstrate the feasibility of this system for the development of a novel glucose sensor.

This study aims to develop a new simple and sensitive method for the microextraction of trace levels of lead in environmental samples. It is based on the use of ionic liquids based dispersive liquid–liquid microextraction (IL–DLLME) before spectrofluorometry.

Cadmium sulphide quantum dots have been synthesised using thioglycolic acid as capping agent through a one-step process with stability and excellent water-solubility, and have strong affinity for lead (Pb). This probe is based on the fluorescence quenching effect of functionalised cadmium sulphide quantum dots.

Factors affecting the extraction efficiency and fluorescence quenching of metals, such as the amount of ionic liquid, amount of metanol, microextraction and centrifugation time, volume of quantum dots and buffer pH, were investigated. Under optimum conditions, the calibration graph was linear in the range of 0.01-3 µg.L-1, with the detection limit of 0.004 µg.L-1 for Pb2+. The relative standard deviation (RSD%, n = 5) of 5.4 per cent at 1 µg.L-1 of Pb2+ was obtained.

This method for pre-concentration of the Pb ions by dispersive liquid–liquid microextraction is novel and could be used for various applications in the synthesis of a wide variety of determination of fluorescence quenching of cadmium sulphide quantum dots.

Based on DNase I and reduced graphene oxide (rGO)-magnetic silicon microspheres (MNPS), a highly sensitive and selective fluorescent probe for the detection of PD-L1 was developed.

Here °C we present a feasibility of biosensor to detection of PD-L1 in lung tumors plasma. In the absence of PD-L1°C the PD-L1 aptamer is absorbed on the surface of graphene oxide modified magnetic nanoparticles °8rGO-MNPS°9 and leading to effective fluorescence quenching. Upon adding PD-L1°C the aptamer sequences could be specifically recognized by PD-L1 and the aptamer/PD-L1 complex is formed°C resulting in the recovery of quenched fluorescence.

This sensor can detect PD-L1 with a linear range from 100 pg mL⁻¹ to 100 ng mL⁻¹, and a detection limit of 10 pg•m⁻¹ was achieved.

This method provides an easy and sensitive method for the detection of PD-L1 and will be beneficial to the early diagnosis and prognosis of tumors.

In this work, A new 4–(2-aminoethylene) amino-N-(2-hydroxyethyl)-1,8-naphthalimide with intense green fluorescent was synthesized. This low molecular weight compound was immobilized by forming a covalent-bond with an acrylonitrile polymer containing carboxylic acid groups. The new prepared dye and self-coloured polymer were characterized by analytical techniques.

The synthesized compounds were characterized by TLC, DSC, FTIR, 1HNMR, 13CNMR, GPC, UV–visible and Fluorometery. The photophysical characteristics of the dye and polymer containing naphthalimide moiety in the side chain, were measured both in the absence and in the presence of Ag⁺, Cd⁺², Co⁺², Cr⁺³, Cu⁺², Fe⁺³, Hg⁺², Ni⁺², Pb⁺² and Zn⁺² cations.

The results showed that the characterization of the synthesized dye and its polymer verified their structural correctness. It is shown that dye and polymer are photo-induced electron transfer (PET) fluorescent sensors which exhibit fluorescence quenching in the presence of metal ions. Among the various metal ions, both dye and polymer are more sensitive to Fe⁺³ cations.

This study is original. A 4–(2-aminoethylene) amino-N-(2-hydroxyethyl)-1,8-naphthalimide and its self-coloured polymer were synthesized for the first time, successfully.

A highly selective cyanide phenoxazine-based fluorescence chemosensor POH was created to detect cyanide (CN) ions.

A malonitrile was added to a phenoxazine fluorophore to make this widely available chemosensor. By fluorescence spectroscopy, the sensor POH showed turn-off fluorescence emission for CN with 2:1 binding stoichiometry in CH₃CN/H₂O (90:10 v/v) medium.

The detection limits for CN were 9.8 × 10⁻⁹ M, which were much lower than WHO standards. NMR and FT-IR investigations backed up the suggested sensor POH mechanism.

The detection CN method should be applicable in a number of situations, where the CN anion for fresh water and drinking water has to be quickly and accurately analyzed.

The technology for optical identification and automatic sorting of products marked with fluorescent materials in trace concentrations is described. A small number of such materials in binary combinations allows marking of a large number of products. The concept has been applied to sort custom‐made domestic plastic products of different types in a fast‐moving mixed stream. The performance of the optical sensor, developed on the basis of identifying fluorescence signatures of some selected markers in these products, has been tested in an industrial singulation and sorting system. Commercially viable sorting rate and purity of “sort” have been demonstrated. The concept is applicable to other industry sectors.

This paper aims to describe the techniques used in industrial optical chemical sensors and to consider future prospects.

This paper discusses the techniques and technologies used in today's optical chemical sensors. It highlights their limitations and considers briefly certain new technological developments.

This paper shows that techniques such as wet reagent‐aided photometry, UV absorption, spectroscopy and UV fluorescence satisfy a range of industrial chemical sensing applications and that optode technology is making limited commercial inroads. It identifies the need for inexpensive, wet reagent‐free chemical sensors and suggests that both solid‐state electrodes and lab‐on‐a‐chip devices may ultimately resolve this issue.

This paper provides a technical insight into the state of optical chemical sensing and illustrates that generic families of inexpensive chemical sensors are yet to be developed.

The paper aims to provide a technical review of the application of quantum dot (QD) technology to sensors.

Following a brief introduction to QD technology, this paper considers recent research on QD‐based physical, chemical and gas sensors.

This shows that QDs are being exploited in a range of experimental sensors for detecting physical variables, notably radiant/electromagnetic quantities and temperature; chemical compounds, such as metals and many species of clinical interest; and a variety of gases and vapours. Prospects also exist to develop improved sources and detectors for use in optical gas sensors.

The paper does not consider biomedical uses of QDs such as cellular imaging, bioassays and biosensors.

This provides a detailed insight into recent research on physical, chemical and gas sensors based on QD technology.

Advanced glycation end products (AGEs) are continuously formed in the body during normal metabolism and ageing through a non‐enzymatic glycosylation reaction between proteins and carbohydrates, known as the Maillard's reaction. Many AGEs are capable of forming cross‐links between proteins and most of them have fluorescent properties. Production of AGEs is markedly increased in diabetes mellitus where they play a pathological role. The aim of the present study is to investigate the possible inhibitory effects of urea, metformin and ascorbic acid on in vitro formation of fluorescent AGE products by comparing their inhibitory capacity with a well‐known AGEs inhibitor, aminoguanidine.

Experiments were carried out using bovine serum albumin and D (+) glucose to produce glycated bovine serum albumin, a fluorescent AGE. Fluorometer analysis was then performed to measure AGEs production and fluorescent intensity was compared between glycated samples with and without the inhibitors.

Aminoguanidine which is known to form guanidine‐carbonyl adduct, reversing the glycation process. was found to inhibit AGEs formation by 57 per cent. Although urea and metformin inhibits glycation by the same route, it was the most effective inhibitor among all four inhibiting agents used. Ascorbic acid, an antioxidant, also inhibits fluorescent AGEs by 52 per cent. It was also a good cross‐link inhibitor. Urea showed an inhibitory effect of 27 per cent. It is suggested that urea formed in the body might be a possible natural protector of AGEs formation. Finally, metformin, an antidiabetic drug inhibits AGEs production by only 12 per cent. It is known to rather increase peripheral sensitivity to insulin and lower blood‐glucose level.

The paper shows that aminoguanidine is the most efficient inhibitor and ascorbic acid supplementation could prove useful in diabetic patients to remove reactive species generated in the Maillard's reaction.

This paper aims to provide a review of the uses of gas sensors to detect explosives' vapours and chemical warfare agents (CWAs).

Following a brief introduction, this paper first considers the use of gas sensors to detect explosives. Second, gas sensors that respond to CWAs are discussed. Some mentioned is made of commercial devices but the emphasis is on emerging technologies and recent research.

Detecting explosives is an emerging application for gas sensors. Despite some commercial products, it is the topic of a major research effort and poses a significant technological challenge due to the very low vapour concentrations involved. Many optical and solid‐state techniques are under development and some have shown ppt levels of resolution to TNT and allied compounds. Detecting CWAs is a far more mature application and many products exist, often based on analytical methods. Nevertheless, research into improved sensing techniques continues, frequently aimed at detecting ppb concentrations of nerve agents. Much of this research is aimed at meeting the needs of, and is being funded by, the US military and security agencies.

This paper provides a technical review of recent developments in the use of gas sensors to detect explosives and CWAs.