A hydrazine-based thiocarbamide probe for colorimetric and turn-on fluorometric detection of PO43− and AsO33− in semi-aqueous medium

2018 ◽  
Vol 42 (8) ◽  
pp. 6236-6246 ◽  
Author(s):  
Rakesh Purkait ◽  
Suvendu Maity ◽  
Chittaranjan Sinha

20% of the population in West Bengal, India is at risk to fatal levels of arsenic. Easy detection of As(iii) is demonstrated by the naked eye using a hydrazine-based thiocarbamide reagent. Limit of detection is 15 nM (AsO33−) at pH 8–12.

RSC Advances ◽  
2015 ◽  
Vol 5 (81) ◽  
pp. 65731-65738 ◽  
Author(s):  
Divya Singhal ◽  
Neha Gupta ◽  
Ashok Kumar Singh

2-((3-Methylthiophen-2-yl)methyleneamino)benzenethiol (Probe 1) is selective for Hg2+. The binding affinity of Hg2+ with Probe 1 was confirmed by DFT and electrochemical behaviour. The limit of detection was 20 μM with 2 : 1 stoichiometry of 1 + Hg2+ complex.


2021 ◽  
Author(s):  
Hyungwook Kim ◽  
Young Jae Jung ◽  
Jungkyu K. Lee

We developed a novel strategy for signal amplification strategy using a visible light-induced photopolymerization, initiated by a selective turn-on photoredox catalyst. As photoredox catalysts, fluorescein derivatives are able to initiate...


2016 ◽  
Vol 237 ◽  
pp. 501-508 ◽  
Author(s):  
Yaming Liu ◽  
Jinyu Zhang ◽  
Jiaxi Ru ◽  
Xiang Yao ◽  
Yang Yang ◽  
...  

2021 ◽  
Author(s):  
Gyeongjin Kim ◽  
Donghwan Choi ◽  
Cheal Kim

Abstract A new benzothiazole-based chemosensor BTN (1-((Z)-(((E)-3-methylbenzo[d]thiazol-2(3H)-ylidene)hydrazono)methyl)naphthalen-2-ol) was synthesized for the detection of Cu2+. BTN could detect Cu2+ with “off-on” fluorescent response from colorless to yellow irrespective of presence of other cations. Limit of detection for Cu2+ was determined to be 3.3 µM. Binding ratio of BTN and Cu2+ turned out to be a 1:1 with the analysis of Job plot and ESI-MS. Sensing feature of Cu2+ by BTN was explained with theoretical calculations, which might be owing to internal charge transfer and chelation-enhanced fluorescence processes.


2018 ◽  
Vol 71 (12) ◽  
pp. 945
Author(s):  
Xin Fu ◽  
He Zhang ◽  
Jie Zhang ◽  
Shi-Tong Wen ◽  
Xing-Cheng Deng

A highly sensitive and label-free microbead-based ‘turn-on’ assay was developed for the detection of Hg2+ in urine based on the Hg2+-mediated formation of intermolecular split G-quadruplex–hemin DNAzymes. In the presence of Hg2+, T–T mismatches between the two partial cDNA strands were stabilized by a T–Hg2+–T base pair, and can cause the G-rich sequences of the two oligonucleotides to associate to form a split G-quadruplex which is able to bind hemin to form the catalytically active G-quadruplex–hemin DNAzyme. This microbead-based ‘turn-on’ process allows the detection of Hg2+ in urine samples at concentrations as low as 0.5 pM. The relative standard deviation and recovery are 1.2–3.9 and 98.7–103.2%, respectively. The remarkable sensitivity for Hg2+ is mainly attributed to the enhanced mass transport ability that is inherent in homogeneous microbead-based assays. Compared with previous developments of intermolecular split G-quardruplex–hemin DNAzymes for the homogeneous detection of Hg2+ (the limit of detection was 19nM), a signal enhancement of ~1000 times is obtained when such an assay is performed on the surface of microbeads.


2018 ◽  
Vol 483 ◽  
pp. 496-503 ◽  
Author(s):  
Bholanath Dolai ◽  
Samiul Islam Hazarika ◽  
Santanab Giri ◽  
Ananta Kumar Atta

2021 ◽  
Vol 21 (4) ◽  
pp. 2123-2131
Author(s):  
Alagan Jeevika ◽  
Dhesingh Ravi Shankaran

A simple, low-cost and highly selective nanosensor was developed for naked-eye detection of mercury ions (Hg2+) based on Eosin/silver nanocubes (Eosin/AgNCbs). Silver nanocubes (AgNCbs) were synthesized by polyol assisted chemical method. HR-TEM result shows the formed AgNCbs have a mean diameter of 84±0.005 nM (diagonally measured) and edge length of 55±0.01 nM. XRD result confirms that the AgNCbs are single crystalline in nature with a phase structure of face centered cubic (FCC) of silver. On interaction of Hg2+, AgNCbs exhibits a color change from gray to black up to 16.67 μM of Hg2+ owed to the formation of solid like bimetallic complex of Ag/Hg amalgam. The selectivity of AgNCbs was evaluated with several other toxic metal ions including, Mg2+, Ba2+, Ca4+, Pb2+, Cd4+, Zn2+, Co2+, Cu2+, K+ and Ni2+ and found good selectivity towards Hg2+. The sensitivity of the AgNCbs sensor system was tuned by using Eosin as a co-staining agent. The Eosin/AgNCbs showed a limit of detection of 60±0.050 nM with the color change from orange to purple. The results suggests that the Eosin/AgNCbs nanosensor exhibits good selectivity, sensitivity, repeatability and rapid response, which could be explored for real-time detection of Hg2+ in environmental and biological samples.


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