Construction of an ultrasensitive non-enzymatic sensor to investigate the dynamic process of superoxide anion release from living cells

• Published in: Biosensors & bioelectronics Vol. 100; pp. 8 - 15
• Main Authors: Wei, Hongwei, Shang, Tianyi, Wu, Tiaodi, Liu, Guoan, Ding, Lan, Liu, Xiuhui
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15.02.2018
• Subjects: Animals; Biosensing Techniques - methods; Catalysis; Dendrimers - chemistry; Electrochemical biosensor; Electrochemical Techniques - methods; Electrodes; Kinetic study; Limit of Detection; Living cell; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; PC12 Cells; Poly(amidoamine) dendrimers; Rats; Silver - chemistry; Silver nanoparticles; Superoxide anion; Superoxides - analysis; Kinetic study; Superoxide anion; Poly(amidoamine) dendrimers; Electrochemical biosensor; Living cell; Silver nanoparticles
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2017.08.046

In this work, a novel non-enzymatic superoxide anion (O2•−) sensor was constructed based on Ag nanoparticles (NPs) / poly (amidoamine) (PAMAM) dendrimers and used to investigate the dynamic process of O2•− release from living cells. The AgNPs/PAMAM nanohybrids were characterized by transmission electron microscopy (TEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The fabricated electrode exhibited excellent catalytic activity toward the reaction of O2•− with a super low detection limit (LOD) of 2.530 × 10–13M (S/N = 3) and wide linear range of 8 orders of magnitude. It could fulfill the requirement of real-time measurement O2•− released from living cells. Furthermore, zymosan was chosen as the stimulant to induce O2•− generation from cancer cells (rat adrenal medulla pheochromocytoma cell (PC12)). The electrochemical experiment results indicated that the levels of intracellular O2•− depended on the amount of Zymosan. A large amount of O2•− generated in the living cells by added heavy stimulant could damage cells seriously. More importantly, a vitro simulation experiment confirmed the role of superoxide dismutase (SOD) for the first time because it could maintain the O2•− concentration at a normal physiological range. These findings are of great significance for evaluating the metabolic processes of O2•− in the biological system, and this work has the tremendous potential application in clinical diagnostics to assess oxidative stress. •Fabricated a novel sensor with PAMAM as effective matrix loading on great amount of AgNPs.•It displays excellent performance toward O2•− with a super low detection limit (2.53 × 10−4nM).•It was used for in situ detecting the O2•− release from living cells with satisfactory results.•Study the kinetics process of O2•− release from living cells for the first time.•The experiment found that SOD could maintain the O2•− concentration at lower lever in biological environment.