Electrochemical detection of superoxide anions in HeLa cells by using two enzyme-free sensors prepared from ZIF-8-derived carbon nanomaterials

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Two kinds of carbon-based nanozymes were constructed from the same precursor of zeolitic imidazolate framework-8 (ZIF-8) for O2•- determination Hollow carbon cubic nanomaterial (labeled as HCC) was obtained by chem. etching ZIF-8 with tannic acid and a subsequent calcination. A porous carbon cubic nanomaterial (labeled as PCC) was prepared by directly pyrolysis. Then HCC and PCC were immobilized on the surface of screen printed carbon electrodes (SPCE), fabricating HCC and PCC modified electrodes (denoted as HCC/SPCE and PCC/SPCE). HCC/SPCE, best operated at -0.5 V (vs. Ag/AgCl), has a sensitivity of 6.55 × 102 nA μM-1 cm-2 with a detection limit of 207 nM (at S/N = 3) for O2•- sensing. And PCC/SPCE, best operated at -0.4 V (vs. Ag/AgCl), exhibited a superior performance for O2•- detection with a sensitivity of 1.14 × 103 nA μM-1 cm-2 and a low detection limit of 140 nM (at S/N = 3). The two sensors possess excellent reproducibility and stability. They were used to sense O2•- released from HeLa cells. [Figure not available: see fulltext.]


CAplus AN 2019:1017574 (Journal)

Last updated on 06/27/2019