Co3S4/MoS2 heterostructure on N-doped porous carbon for boosted peroxidase-like activity and sensitive biosensing

To improve the peroxides-like activities of metal sulfides as nanozymes, Co3S4/MoS2 heterostructure were designed and fabricated, then being anchored on N doped porous carbon (NPC). In the work, cyclic voltammetry (CV), the electron accepting ability verified by coenzyme Q10, contact angle, Michaelis−Menten kinetics parameters (Km and Vmax) and XPS of Co3S4/MoS2@NPC and relevant references were employed to explore the catalytic mechanism and structure−activity relationship, and results show that Co3S4/MoS2@NPC can encourage the electron transfer between substrates and catalysts with the help of Co-S-Mo band in the heterointerface and has an even higher affinity to TMB and H2O2 than that of the other related nanozyme, attributed to higher conductivity, larger surface area, higher porosity, and good hydrophilicity and wettability of NPC. As a consequence, compared with single Co3S4 and MoS2, also Co3S4 + MoS2, the catalytic activity of Co3S4/MoS2 was improved by 4-times, 5-times and 2-times, showing a lower limit of 0.26 μmol/L for H2O2 detection in linear range from 0 to 200 μmol/L, and Co3S4/MoS2@NPC shows the lowest limit of detection (0.0087 μmol/L) in the range of 5 ∼ 200 μmol/L and good selectivity to xanthine, to the best our knowledge.