Cobalt Phosphates Loaded into Iodine-Spaced Reduced Graphene Oxide Nanolayers for Electrochemical Measurement of Superoxide Generated by Cells

Cobalt phosphate (Co3(PO4)2) has been recognized as a biomimetic superoxide anion (O2•–) sensing material, but there is a great challenge to achieve high sensitivity due to its relatively poor conductivity. Here, a unique nanostructure is synthesized by using iodine nanospacer-impregnated reduced graphene oxide (I-rGO) layers to nest Co3(PO4)2. The role of iodine greatly enhances the density of nanoscale Co3(PO4)2 catalytic centers by separating reduced rGO layers while accelerating the interfacial electron transfer and followed transport through the directionally arranged conductive grapheme layers. The Co3(PO4)2/I-rGO sensor delivers a very good selectivity with a higher sensitivity, shorter response time, and wider linear range than that of Co3(PO4)2/rGO without the iodine nanospacers toward O2•– detection, and also the reported Co3(PO4)2 nanorods work. Furthermore, the sensor was used to detect O2•– generated by prostate cancer cells. This study holds promise for a high value nanoscale biomimetic sensor in practical clinical and bioresearch applications and also demonstrates a rational merit-hybrid nanocomposite design by offering critical contributions from individual components into the biomimetic sensing platform.