scholarly journals A Simple and Label-Free Detection of As3+ using 3-nitro-L-tyrosine as an As3+-chelating Ligand

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2857 ◽  
Author(s):  
Jin-Ho Park ◽  
Gyuho Yeom ◽  
Donggu Hong ◽  
Eun-Jung Jo ◽  
Chin-Ju Park ◽  
...  
Keyword(s):  
Detection Method ◽  
Color Change ◽  
Specific Property ◽  
Quantitative Detection ◽  
Label Free ◽  
Real Samples ◽  
Real Water Samples ◽  
Label Free Detection ◽  
Reaction Stoichiometry ◽  
Site Binding

A simple and rapid As3+ detection method using 3-nitro-L-tyrosine (N-Tyr) is reported. We discovered the specific property of N-Tyr, which specifically chelates As3+. The reaction between As3+ and N-Tyr induces a prompt color change to vivid yellow, concomitantly increasing the absorbance at 430 nm. The selectivity for As3+ is confirmed by competitive binding experiments with various metal ions (Hg2+, Pb2+, Cd2+, Cr3+, Mg2+, Ni2+, Cu2+, Fe2+, Ca2+, Zn2+, and Mn2+). Also, the N-Tyr binding site, binding affinity, and As3+/N-Tyr reaction stoichiometry are investigated. The specific reaction is utilized to design a sensor that enables the quantitative detection of As3+ in the 0.1–100 μM range with good linearity (R2 = 0.995). Furthermore, the method’s applicability for the analysis of real samples, e.g., tap and river water, is successfully confirmed, with good recoveries (94.32–109.15%) using As3+-spiked real water samples. We believe that our discovering and its application for As3+ analysis can be effectively utilized in environmental analyses such as those conducted in water management facilities, with simplicity, rapidity, and ease.

scholarly journals A label-free detection of diethylstilbestrol based on molecularly imprinted polymer-coated upconversion nanoparticles obtained by surface grafting

RSC Advances ◽  
2017 ◽  
Vol 7 (36) ◽  
pp. 22215-22221 ◽  
Author(s):  
Yu Wang ◽  
Shuyue Ren ◽  
Huicong Jiang ◽  
Yuan Peng ◽  
Jialei Bai ◽  
...  
Keyword(s):  
Molecularly Imprinted Polymer ◽  
Fluorescent Sensor ◽  
Upconversion Nanoparticles ◽  
Surface Grafting ◽  
The Novel ◽  
Label Free ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Real Samples ◽  
Label Free Detection

The novel MIPs-coated UCNPs fluorescent sensor could be used for on-field detection of diethylstilbestrol in real samples.

scholarly journals Label-free detection of Phytophthora ramorum using surface-enhanced Raman spectroscopy

The Analyst ◽  
2015 ◽  
Vol 140 (21) ◽  
pp. 7254-7262 ◽  
Author(s):  
Sezin Yüksel ◽  
Lydia Schwenkbier ◽  
Sibyll Pollok ◽  
Karina Weber ◽  
Dana Cialla-May ◽  
...  
Keyword(s):  
Surface Enhanced Raman Spectroscopy ◽  
Analytical Tool ◽  
Phytophthora Ramorum ◽  
Label Free ◽  
Specific Detection ◽  
Real Samples ◽  
Label Free Detection ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Species Specific

Label-free and species-specific detection of the plant pathogen Phytophthora ramorum from real samples employing SERS as an analytical tool.

scholarly journals Silicene Quantum Capacitance Dependent Frequency Readout to a Label-free Detection of DNA Hybridization

2021 ◽  
Author(s):  
Sazzadur Rahman ◽  
Rokaia Laizu Naima ◽  
Khatuna Jannatun Shetu ◽  
Mahabub Hossain ◽  
M. Shamim Kaiser ◽  
...  
Keyword(s):  
Band Gap ◽  
Dna Hybridization ◽  
Glucose Sensor ◽  
Detection Method ◽  
Genetic Research ◽  
Ph Sensor ◽  
Detection Methods ◽  
Quantum Capacitance ◽  
Label Free ◽  
Label Free Detection

Two-dimensional silicon allotrodes– also called Sinicene– have recently experienced intensive scientific research interest due to their unique electrical, mechanical, and sensing characteristics. A novel silicene based nano-material has been enticed great amenities, partially because of its uniformity with graphene. Silicene is a highly sensitive for numerous sensors based on molecular sensing as pH sensor, gas sensor, ion sensor and biosensing are Deoxyribonucleic acid (DNA) nucleobase sensor, photonic sensor, cell-based biosensor, glucose sensor, and bioelectric nose sensor. Nowadays genetic research based on DNA hybridization, which is a vital tools for sensing material and it has various detection methods. Among of them, the detection method is frequency readout used to a label-free detection of DNA hybridization. In this paper we have compared the graphene and silicene quantum capacitance that has been proposed for a DNA hybridization detection method on wireless readout. These method shows, the strands of mismatched and complementary DNA have in different range of frequency to identify output efficiency. With respect to DNA concentration the output of silicene is almost sharply linear than graphene. In addition of field effect transistor, silicene opens a new opportunities due to its band gap whereas graphene indicates zero band gap. It can be stated that silicene is much more reliable as well as much stronger than multi-layered graphene.

scholarly journals Development of an Impedimetric Aptasensor for Label Free Detection of Patulin in Apple Juice

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1017 ◽  
Author(s):  
Reem Khan ◽  
Sondes Ben Aissa ◽  
Tauqir Sherazi ◽  
Gaelle Catanante ◽  
Akhtar Hayat ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Apple Juice ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Diazonium Salt ◽  
Specific Interaction ◽  
Quantitative Detection ◽  
Label Free ◽  
Analytical Technique ◽  
Label Free Detection

In the present work, an aptasensing platform was developed for the detection of a carcinogenic mycotoxin termed patulin (PAT) using a label-free approach. The detection was mainly based on a specific interaction of an aptamer immobilized on carbon-based electrode. A long linear spacer of carboxy-amine polyethylene glycol chain (PEG) was chemically grafted on screen-printed carbon electrodes (SPCEs) via diazonium salt in the aptasensor design. The NH2-modified aptamer was then attached covalently to carboxylic acid groups of previously immobilized bifunctional PEG to build a diblock macromolecule. The immobilized diblocked molecules resulted in the formation of long tunnels on a carbon interface, while the aptamer was assumed as the gate of these tunnels. Upon target analyte binding, the gates were assumed to be closed due to conformational changes in the structure of the aptamer, increasing the resistance to the charge transfer. This increase in resistance was measured by electrochemical impedance spectroscopy, the main analytical technique for the quantitative detection of PAT. Encouragingly, a good linear range between 1 and 25 ng was obtained. The limit of detection and limit of quantification was 2.8 ng L−1 and 4.0 ng L−1, respectively. Selectivity of the aptasensor was confirmed with mycotoxins commonly occurring in food. The developed apta-assay was also applied to a real sample, i.e., fresh apple juice spiked with PAT, and toxin recovery up to 99% was observed. The results obtained validated the suitability and selectivity of the developed apta-assay for the identification and quantification of PAT in real food samples.

Simple label-free fluorescence detection of apurinic/apyrimidinic endonuclease 1 activity and its inhibitor using the abasic site-binding fluorophore

2019 ◽  
Vol 11 (6) ◽  
pp. 739-743 ◽  
Author(s):  
Xuejun Li ◽  
Mei Xiong ◽  
Yufeng Huang ◽  
Liangliang Zhang ◽  
Shulin Zhao
Keyword(s):  
Fluorescence Detection ◽  
Detection Method ◽  
Label Free ◽  
Abasic Site ◽  
Site Binding

A label-free fluorescence detection method for apurinic/apyrimidinic endonuclease 1 activity was reported based on the abasic site-binding fluorophore.

scholarly journals Strong binding and fluorescence sensing of bisphosphonates by guanidinium-modified calix[5]arene

2018 ◽  
Vol 14 ◽  
pp. 1840-1845 ◽  
Author(s):  
Jie Gao ◽  
Zhe Zheng ◽  
Lin Shi ◽  
Si-Qi Wu ◽  
Hongwei Sun ◽  
...  
Keyword(s):  
Salt Bridge ◽  
Quantitative Detection ◽  
Label Free ◽  
Fluorescence Sensing ◽  
Buffer Solution ◽  
Biologically Relevant ◽  
Strong Binding ◽  
Label Free Detection ◽  
Artificial Urine ◽  
Set Up

Based on the indicator displacement assay (IDA) approach, we herein report the fluorescence “switch-on” sensing and quantitative detection of bisphosphonates (BPs), a class of drugs extensively used in the treatment of patients with various skeletal diseases. Guanidinium-modified calix[5]arene (GC5A) affords strong binding on the micromolar to nanomolar level towards BPs dominantly via multiple salt bridge interactions, which was evaluated by fluorescence competitive titrations. Fluorescent IDA enables the highly sensitive and label-free detection of BPs in buffer solution, and more importantly, in artificial urine. Calibration lines were therefore set up in untreated artificial urine, allowing for quantifying the concentrations of BPs in the biologically relevant low range.

scholarly journals A Differential Detection Method Based on a Linear Weak Measurement System

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2473
Author(s):  
Nian Xiong ◽  
Tian Guan ◽  
Yang Xu ◽  
Lixuan Shi ◽  
Suyi Zhong ◽  
...  
Keyword(s):  
Measurement System ◽  
Total Internal Reflection ◽  
High Stability ◽  
Detection Method ◽  
Weak Measurement ◽  
Internal Reflection ◽  
Differential Detection ◽  
Label Free ◽  
Label Free Detection ◽  
Linear Differential

Self-reference detection is necessary and important to a biosensor. The linear weak measurement system based on total internal reflection has attracted widespread attention due to its high stability, label-free detection, and easy integration. In this paper, we propose a differential detection method based on the linear total internal reflection weak measurement system. We introduce the half-wave plate (HWP) to convert the H light and the V light to each other, thereby obtaining the difference in phase change of the optical path before and after the HWP. Experiments show that the system can not only achieve differential detection, but also has high stability. The linear differential weak measurement system proposed in this paper not only provides a new differential measurement method for real-time biosensors, but also enriches the types of weak measurement sensors.

A smartphone-based fiber-optic aptasensor for label-free detection of Plasmodium falciparum glutamate dehydrogenase

2020 ◽  
Vol 12 (10) ◽  
pp. 1333-1341
Author(s):  
Manoharan Sanjay ◽  
Naveen K. Singh ◽  
Lightson Ngashangva ◽  
Pranab Goswami
Keyword(s):  
Plasmodium Falciparum ◽  
Glutamate Dehydrogenase ◽  
Fiber Optic ◽  
Quantitative Detection ◽  
Optic Fiber ◽  
Label Free ◽  
Label Free Detection

A novel smartphone-based, multi-channel, optic fiber platform for quantitative detection of Plasmodium falciparum glutamate dehydrogenase (PfGDH) has been explored in this study.

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