3D Tetrametallic Dendrite-Based Non-Enzymatic Sensor Coupled with a Smartphone Interface for GSH Quantification in Biological Fluids and Ex Vivo Rat Models

Non-enzymatic platforms, based on inorganic nanomaterials, are emerging as promising alternatives to traditional enzyme-based platforms in catalytic applications. Recently, fern or tree like metallic dendrites have attracted growing interest for detection of target analytes due to their distinctive hierarchical branched morphology. It imparts dendrites' large specific surface area and hence a multitude of catalytic centers. In light of its significant functional properties, we attempted to synthesize a tetrametallic dendrite-based non-enzymatic sensing platform for direct detection of glutathione (GSH), which plays a crucial role in maintaining a redox balance in living organisms. However, when the body is under oxidative stress, its level drops, resulting in several clinical manifestations in the body. Therefore, the quantification of GSH continues to be the central focus of investigation among researchers. This study aims to develop a stable 3D tetrametallic dendritic non-enzymatic interface, an efficient alternative to enzyme-based systems for sensitive detection of GSH. The sensor demonstrated exceptional analytical performance, possessing a wide linearity between 0.05 and 200,000 nM and an impressively low detection limit of 0.02 nM. The non-enzymatic sensor reliably detects GSH in human serum samples with recovery percentages ranging between 91.17% and 99.73%. The developed tetrametallic interface was further employed to evaluate GSH levels in a diquat-induced rat model using plasma and liver homogenate samples. The outcomes showed that with increasing time following diquat administration and with increasing dosage of diquat, oxidative stress intensifies, accompanied by a progressive depletion of GSH. Furthermore, the smartphone integration with a developed sensor is an extended functionality of the nanoelectronic platform. It has the potential to be deployed on-site since it automates data processing and distinguishes healthy from critically low GSH levels in real samples. The rapid on-chip fabrication within 15 min and its smartphone integration highlight the potential for automated tracking in point-of-care diagnosis.