Preparation of ultra-sensitive and selective hydrogen peroxide-based colorimetric sensor using highly exfoliated
Mohib Ullah1, Roopashree R2, Prakash Kanjariya3
1School of Material Science and Engineering, Henan University of Technology Zhengzhou, Zhengzhou, 450001, Henan, China. mohib3086@gmail.com.
Abstract:
A highly sensitive, portable, rapid, and accurate colorimetric sensing method is presented. It is based upon exfoliated g-C3N4 nanosheets (E-g-C3N4 NSs), having peroxidase nanozyme-like properties. The as-prepared catalyst (E-g-C3N4 NSs) tends to oxidize the colorless tetramethyl-benzidine (TMB) into oxidized-TMB in the presence of hydrogen peroxide (H2O2) generating a dark blue color and corresponding ultraviolet visible-spectral changes following a Michaelis-Menten kinetic. The prepared colorimetric sensor exhibited response within the range 0.001-0.450 μM having R2 value of 0.999 and a detective limit (LOD) of 0.15 ± 0.04 nM. Furthermore, the sensor also displayed outstanding selectivity, ample stability (10 weeks), and excellent practicability in real sample applications. All these outstanding properties were highly attributed to the large surface area with exposed actives sites, high surface energy, and large conductive structure of E-g-C3N4 NSs. For comparison of the catalytic study, we have also explored the sensing mechanism of B-g-C3N4, using the same optimized experimental conditions. Resultantly, we concluded that the proposed sensor (E-g-C3N4 NSs) will gain considerable attention for on-site environmental and health monitoring in future endeavor.
