Portable visual and electrochemical detection of hydrogen peroxide release from living cells based on dual functional Pt-Ni hydrogels

Abstract

It is of great significance to monitor the intra-/extra-cellular concentration of hydrogen peroxide (H2O2) in biological processes. However, miniaturized devices that realize portable and accurate H2O2 detection are still at an infant stage because of the difficulties to develop facile sensing strategies and further highly-integrated sensing devices. In this work, portable H2O2 sensors are demonstrated based on Pt-Ni hydrogels with excellent peroxidase-like and electrocatalytic activities. Thus, simple and sensitive H2O2 sensing is achieved through both colorimetric and electrochemical strategies. The as-fabricated H2O2 sensing chips exhibit favorable performances such as low detection limits (0.03 μM & 0.15 μM), wide linearity ranges (0.1 μM-10 mM & 0.5 μM-5 mM), outstanding long-term stability (up to 60 days), and excellent selectivity. With the aid of an M5stack development board, portable visual and electrochemical H2O2 sensors are successfully constructed without complicated and expensive equipment as well as professional operators. When applied in the H2O2 detection released from the Hela cells, the obtained results are in good agreement with those from an ultraviolet-visible spectrophotometer (UV-vis) (1.97 μM vs. 2.08 μM) and electrochemical station (1.77 μM vs. 1.84 μM), respectively.