Dispersible mesoporous carbon nanospheres as active electrode materials for biomolecular sensing

•Soft templated mesoporous carbon nanosphere (MCNS) as an active electrode material.•Good accessibility of MCNS was exemplified by simultaneous detection of biomolecules.•Conductive nonporous carbon and inert mesoporous silica nanospheres were designed too.•A comparative study on three nanospheres was performed for intrinsic activity of MCNS.•Both pores and carbon skeleton with defects are beneficial to the activity of MCNS.

Mesoporous carbon electrode materials have attracted attention in analytical chemistry and materials science, particularly in the electrochemical determination of biomolecules, because of their open-pore structure, large surface area, and high electrochemical activity. In this study, novel mesoporous carbon nanospheres (MCNSs) with open-pore structure, which is beneficial in preparing dispersible phases of powders for sensor fabrication, were designed and synthesized using a facile soft template approach. The accessibility of the MCNS-based active electrode material was demonstrated by simultaneous determination of dopamine, ascorbic acid, and uric acid at physiological pH. The dispersibility of MCNS was manifested by the improved stability and reproducibility of the fabricated electrochemical sensor. Meanwhile, another two similar nanospheres, namely, carbon nanospheres without open-pore structure and electrochemically inert mesoporous silica nanospheres, were also fabricated to determine the origin of the catalytic activity of the MCNSs. The high activity of the MCNS-based electrode materials can be attributed to their nanoporous structure and conductive carbon skeleton that contains high degree of defects. In addition, highly open nanopores allowed easy access of the targets to the defective sites on the nanopore walls, thereby enhancing catalytic activity and reducing response time.

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