Development of Gelatin-Alginate-TiO2-SOD Biosensor for the Detection of Superoxide Radicals

Abstract

In this work, a biosensor that uses gelatin and alginate hydrogels in addition to titaniumdioxide (TiO2) nanoparticles (NPs) as a sensor matrix was developed to detect superoxide radicals(O2•-), which play a role in carcinogenesis when present in excess levels. Parameters affecting theperformance of the biosensor such as the amount of gelatin-alginate ratio, amount of TiO2 NPs, theconcentration of SOD enzymes, and glutaraldehyde (GA) cross-linker were investigated.Chronoamperometry was used as an electrochemical technique for the development of biosensor aswell as characterization steps. The developed biosensor exhibited two linear ranges between 0.0009mM – 0.125 mM and 0.25 mM – 2 mM, which was utilized as calibration curves. The detection limit ofthe biosensor was found 0.9 μM, which was at the appropriate level for the detection of O2•- in tumorsamples. Finally, the constructed biosensor showed significant analytical performance, such as lowdetection limit, reusability, and reproducibility.