Enhancing Enzyme-like Activities of Prussian Blue Analog Nanocages by Molybdenum Doping: Toward Cytoprotecting and Online Optical Hydrogen Sulfide Monitoring

Abstract

Artificial nanozymes have been designed to solve the problems of high cost and poor stability involving natural enzymes in analytical applications. Nevertheless, the catalytic efficiency of the nanozyme still needs to be improved so that it can meet the stability and sensitivity requirements of continuous biological detection. We presented an effective tailoring strategy to enhance the enzyme-like activities of Prussian-blue-analog-based nanozymes. Molybdenum-polysulfide-deposited nickel–iron bimetal Prussian-blue-analog-based hollow nanocages (Nanocages) with peroxidase-, catalase-, and laccase-mimicking activities were synthesized. The doping of molybdenum successfully tailored the size, morphology, composition, and complex structure of the Nanocage, and the peroxidase- and laccase-mimicking activities of the Nanocage nanozyme were enhanced by over 37 and 27 times, respectively, compared with pristine Prussian blue analogs. Moreover, in environments of harsh pH, high temperature, and high salt concentration, Nanocages exhibited much higher stability than natural enzymes. The peroxidase- and catalase-mimicking activities were applied to eliminate reactive oxygen species in cells, whereas the laccase-like activity of Nanocages was integrated with an online sensing platform for in vivo and continuous optical hydrogen sulfide monitoring in the brains of living rats. Our findings may provide possibilities for advancing the design strategy of highly active nanozymes as well as nanozyme-based in vivo detection methods and will offer unique opportunities for their involvement in bioanalytical chemistry.

The age of bioinspired molybdenum‐involved nanozymes: Synthesis, catalytic mechanisms, and biomedical applications

“…Reproduced with permission. 120 Copyright 2020, American Chemical Society cer cells. In another study, an ultrasensitive electrochemical circulating tumor cells (CTCs) detection strategy was developed based on reduced graphene oxide/molybdenum disulfide (rGO/MoS 2 ) NSs and immunomagnetic beads Fe 3 O 4 NPs dual enzyme mimics synergistic catalysis for signal amplification.…”

Synthesis, Catalytic Properties and Application in Biosensorics of Nanozymes and Electronanocatalysts: A Review

“…The enzyme-like properties of PBA in solution are difficult to analyze because of the ability of PB and PBAs to simultaneously mimic the activities of several ROS-enzymes (PO, SOD and catalase). Numerous papers (see Table 6) described the ability of PBA-NZ to react with typical ROS-enzyme substrates, such as TMB, ABTS and NADH [169]. PB and PBAs are used successfully in optical biosensors as a result of their PO-like properties [12,16,[169][170][171][172][173][174][175].…”

“…Numerous papers (see Table 6) described the ability of PBA-NZ to react with typical ROS-enzyme substrates, such as TMB, ABTS and NADH [169]. PB and PBAs are used successfully in optical biosensors as a result of their PO-like properties [12,16,[169][170][171][172][173][174][175]. The first communications concerning electrochemical reduction of H 2 O 2 on PB-modified glassy carbon electrode were done by Itaya and colleagues [164,165].…”

“…In 2000, this group named PB an "artificial PO" [177]. At the same time, a large number of other scientific groups, especially from China, worked hard on this problem [148,154,[156][157][158][159]166,[168][169][170][171][172][173][174].…”

“…PB and PBAs are used successfully in optical biosensors as a result of their PO-like properties [ 12 , 16 , 169 , 170 , 171 , 172 , 173 , 174 , 175 ]. The first communications concerning electrochemical reduction of H 2 O 2 on PB-modified glassy carbon electrode were done by Itaya and colleagues [ 164 , 165 ].…”