Dual-mode label-free electrochemical immunosensor for ultrasensitive detection of procalcitonin based on g-C3N4-NiCo2S4-CNTs-Ag NPs

The Analyst ◽  
2021 ◽  
Author(s):  
Xiaoting Xu ◽  
Xuan Li ◽  
Juncong Miao ◽  
Lei Liu ◽  
Xinyi Huang ◽  
...  

Herein, a label-free electrochemical immunosensor which based on Differential Pulse Voltammetry (DPV) and Amperometric i-t curve (i-t) dual-mode analysis is proposed for early quantitative detection of procalcitonin (PCT). Thanks to...

2020 ◽  
Vol 10 (2) ◽  
pp. 191-199
Author(s):  
Santhy Wyantuti ◽  
Uji Pratomo ◽  
Shauvina A Shauvina ◽  
Yeni Wahyuni Hartati ◽  
Husein Hernandi Bahti

Dysprosium has gained global interest due to its key application in renewable technology, such as wind power technology. The presence of this rare earth element (REE) can be determined by several spectroscopic methods. Recently, a voltammetry method has provided an alternative method for the simple and fast detection of REEs. However, to the best of our knowledge, this experiment is usually carried out in an aqueous solvent, and the response of the REE in an organic solvent by the voltammetry method has rarely been investigated. In this research, the quantitative detection of dysprosium and dysprosium mixtures with samarium, europium and gadolinium in acetonitrile is reported by differential pulse voltammetry. A Box-Behnken design was applied to predict the optimum condition of the measurements. Three factors, namely potential deposition, deposition time and amplitude modulation, were found to significantly influence the signal under optimal conditions, which are -1.0 V, 83.64 s and 0.0929 V, respectively. The surface characterization of dysprosium deposited on a Pt surface shows better deposition under 100% acetonitrile compared to a lower concentration of acetonitrile. The evaluation in this study shows a detection limit of 0.6462 mg•L-1 and a quantitation limit of 2.1419 mg•L-1, with a precision value and recovery value of 99.97% and 93.62%, respectively.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Zheng Li ◽  
Yong Zhang ◽  
Jiaye Ye ◽  
Meiqing Guo ◽  
Jing Chen ◽  
...  

In the present research, a nonenzymatic glucose biosensor was fabricated by depositing Ag nanoparticles (Ag-NPs) using in situ chemical reduction method on TiO2nanotubes which were synthesized by anodic oxidation process. The structure, morphology, and mechanical behaviors of electrode were examined by scanning electron microscopy and nanoindentation. It was found that Ag-NPs remained both inside and outside of TiO2nanotubes whose length and diameter were about 1.2 μm and 120 nm. The composition was constructed as an electrode of nonenzymatic biosensor for glucose oxidation. The electrocatalytic properties of the prepared electrodes for glucose oxidation were investigated by cyclic voltammetry (CVs) and differential pulse voltammetry (DPV). Compared with bare TiO2and Ag-fresh TiO2nanotube, Ag-TiO2/(500°C) nanotube exhibited the best electrochemical properties from cyclic voltammetry (CVs) results. Differential pulse voltammetry (DPV) results showed that, at +0.03 V, the sensitivity of the electrode to glucose oxidation was3.69 mA⁎cm-2⁎mM-1with a linear range from 20 mM to 190 mM and detection limit of 24 μM (signal-to-voice ratio of 3). In addition the nonenzymatic glucose sensors exhibited excellent selectivity, stability, and repeatability.


2003 ◽  
Vol 10 (2) ◽  
pp. 155-164 ◽  
Author(s):  
Clarissa Pires de Castro ◽  
Jurandir SouzaDe ◽  
Carlos Bloch Jr

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.


1991 ◽  
Vol 56 (3) ◽  
pp. 595-601 ◽  
Author(s):  
Jiří Barek ◽  
Gulamustafa Malik ◽  
Jiří Zima

Optimum conditions were found for the determination of 4-nitrobiphenyl by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-5 to 2 . 10-7 mol l-1. A further increase in sensitivity was attained by adsorptive accumulation of this substance on the surface of the working electrode, permitting determination in the concentration range (2 – 10) . 10-8 mol l-1 with one minute accumulation of the substance in unstirred solution or (2 – 10) . 10-9 mol l-1 with three-minute accumulation in stirred solution. Linear scan voltammetry can be used to determine 4-nitrobiphenyl in the concentration range (2 – 10) . 10-9 mol l-1 with five-minute accumulation in stirred solution, with the advantage of a smoother baseline and smaller interference from substances that yield only tensametric peaks.


2021 ◽  
Author(s):  
Xiangrong Huang ◽  
Na Wu ◽  
Wenxiu Liu ◽  
Yazhuo Shang ◽  
Honglai Liu ◽  
...  

In this work, a novel redox hydrogel was proposed for ultrasensitive label-free electrochemical detection of carcinoembryonic antigen (CEA). The redox hydrogel composed by cellulose nanocrystalline (CNC), methylene blue (MB), multi-walled...


The Analyst ◽  
2021 ◽  
Author(s):  
Xinke Liu ◽  
Lu-Yin Lin ◽  
Fu-Yen Tseng ◽  
Yu-Cheng Tan ◽  
Jian Li ◽  
...  

Matrix metalloproteinase-1 (MMP-1) is associated with many types of cancers, including oral, colorectal, and brain cancers. This paper describes the fabrication of an MMP-1 immunosensor based on a gold nanoparticle/polyethyleneimine/reduced...


2021 ◽  
Author(s):  
Yan Jin ◽  
Tong QI ◽  
Yuqing Ge ◽  
Jin Chen ◽  
Li juan Liang ◽  
...  

In this paper, ultrasensitive electrochemical determination of phosphate in water is achieved by hydrophilic TiO2 modified glassy carbon electrodes for the first time. Differential pulse voltammetry (DPV) method is proposed...


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