Construction of a novel electrochemical sensing platform to investigate the effect of temperature on superoxide anions from cells and superoxide dismutase enzyme activity

It is of great significance to realize the detection of trace amounts of superoxide anions (O-2 center dot(-)) in biological systems due to the connection between the concentration of O-2 center dot(-) and some diseases. Here, we present a novel method to fabricate a non-enzymatic electrochemical sensor for measuring O-2 center dot(-) from biological systems. The sensor was fabricated by nanocomposites (PAMAM-Au) synthesized by using (PAMAM-G4.0) dendrimers as template/stabilizers for gold nanoparticles (AuNPs) growth. Transmission electron microscopy (TEM) investigations indicate that AuNPs were encapsulated in PAMAM with average diameter about 8 nm. The electrochemical technique confirmed that PAMAM-Au possessed extraordinary electrochemical response to superoxide anions. As an analytical and sensing platform, apart from excellent sensitivity, wide liner range (from 3.69 x 10(-5) - 37.2 mu M), ultra-low detection limit (0.0123 nM), our sensor also presented satisfying performance for monitoring changes of O-2 center dot(-) levels upon different stimuli. Furthermore, we investigated the effect of temperature on superoxide anions released from living cells and enzyme activity through an electrochemical method for the first time. Most importantly, the simulated electrochemical study in vitro further confirmed that temperature has a crucial influence on both the ability of living cells to resist external stimulation and the antioxidant capacity of superoxide dismutase. As expected, the study may provide researchers with potential value for understanding the temperature effects on organisms and the treatment of diseases caused by oxidative stress. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study presents a novel non-enzymatic electrochemical sensor for detecting superoxide anions in biological systems, showing excellent performance and wide application prospects. The research also explores the impact of temperature on the release of superoxide anions from living cells and enzyme activity for the first time, providing crucial insights into understanding the effects of temperature on organisms and treating diseases caused by oxidative stress.