Defective Prussian Blue Analogue with Cobalt for Fabrication of An Electrochemical Sensor for Detecting Ascorbic Acid, Dopamine and Uric Acid

Abstract

A Prussian blue analogue with cobalt (Na2‐xCo[Fe(CN)6]1‐y, PB‐Co), which is often used as sodium‐ion battery material, was found to be an excellent sensing material toward some biomolecules by calcination. PB‐Co calcined at 750 °C for 1 h (PB‐Co750‐1) has the improved defects to facilitate the adsorption and the catalytic oxidation of ascorbic acid (AA), dopamine (DA) and uric acid (UA). PB‐Co750‐1 modified on screen printed carbon electrode (SPE) for the ultrasensitively simultaneous determination of AA, DA and UA demonstrates the wide linear range, the low limit of detection (LOD) and the good reproducibility. In addition, the redox of the analytes was confirmed as the diffusion‐controlled process via the kinetic study. The recoveries of AA, DA and UA in real samples were found between 91 % to 114 %. AA and UA in tablets, serums and urines could be determined by PB‐Co750‐1/SPE with the satisfactory results.

Electrochemical Sensors based on Gold–Silver Core–Shell Nanoparticles Combined with a Graphene/PEDOT:PSS Composite Modified Glassy Carbon Electrode for Paraoxon-ethyl Detection

“…In addition, the catalytic rate constant can be determined using the slope of the I C / I L vs t 1/2 as shown in Figure 5 E following the equation below: where I C is the catalytic current of paraoxon-ethyl reduction using Au–Ag core–shell/graphene/PEDOT:PSS/GCE, I L is the limiting current in the absence of paraoxon-ethyl (A), k h is the catalytic rate constant (L mol –1 s –1 ), C is the concentration of paraoxon-ethyl (mol L –1 ), and t is the experiment time (s). On the basis of this equation, it can be derived that the catalytic rate constant ( k h ) for the paraoxon-ethyl reduction using this modified electrode is 1.98 × 10 3 L mol –1 s –1 , which is proportional to the value reported in previous studies (5.88 × 10 3 L mol –1 s –1 as reported in ref ( 70 ) and 2.25 × 10 3 L mol –1 s –1 as reported in ref ( 71 )).…”

“…On the basis of this equation, it can be derived that the catalytic rate constant (k h ) for the paraoxon-ethyl reduction using this modified electrode is 1.98 × 10 3 L mol −1 s −1 , which is proportional to the value reported in previous studies (5.88 × 10 3 L mol −1 s −1 as reported in ref 70 and 2.25 × 10 3 L mol −1 s −1 as reported in ref 71). Electroanalytical Performance of Au−Ag Core−Shell/ Graphene/PEDOT:PSS/GCE for Paraoxon-ethyl Detection.…”

A Portable Electrochemical Dopamine Detector Using a Fish Scale-Derived Graphitized Carbon-Modified Screen-Printed Carbon Electrode

“…The catalytic rate constant (k cat ) of DA oxidation could be obtained using the following equation [41]: I cat /I L = (πk cat C 0 t) 1/2 , where I cat and I L are the current on the a-GC/SPCE in the presence and absence of DA, respectively, and t is the elapsed time. From the slope of the I cat /I L vs. t 1/2 plot (Figure 5D), the value of k cat was found to be 5.48 × 10 4 M −1 s −1 , which was obviously larger than that reported in the literature (8.81 × 10 3 M −1 s −1 [42], 2.57 × 10 4 M −1 s −1 [43], 6.80 × 10 2 M −1 s −1 [44]). The results prove that a-GC has good electrocatalytic activity for electrochemical oxidation of DA.…”

Nanocubic cobalt-containing Prussian blue analogue-derived carbon-coated CoFe alloy nanoparticles for noninvasive uric acid sensing

“…The preparation of PCF referred to the reported works with some difference. 41,42 Briefly, CoCl 2 ·6H 2 O and trisodium citrate were dissolved in 50 mL water to form a citrate 3− –Co 2+ chelate solution, where the molar ratio of CoCl 2 and trisodium citrate was always consistent as 1 : 1.2 with a molar change of CoCl 2 . Then, the chelate solution and 50 mL Na 4 Fe(CN) 6 (0.1 M) were added dropwise to 100 mL water with magnetic stirring to form a precipitate slowly.…”