Lab-on-Chip device based on aptamers for real-time zinc ion detection: advancing on-site environmental monitoring

Background: While low levels of zinc are generally harmless, elevated concentrations can lead to significant contamination, making their monitoring crucial for environmental and health applications. Traditional methods for zinc detection often rely on bulky and complex equipment, making them impractical for on-site analysis. The development of a Lab-on-Chip device for zinc sensing offers the advantage of in-field analysis, enabling real-time monitoring of zinc levels. This capability allows for prompt intervention and potential cost reductions. Results: In this study, an aptamer with high affinity for zinc ions was initially characterized in solution using emission spectroscopy, employing two distinct fluorescence assay strategies. Based on these findings, the aptamer was immobilized within microfluidic channels and integrated with an array of amorphous silicon photosensors (a-Si:H) for fluorescence detection. This advanced setup enables on-chip detection of the fluorescent signals arising from the interaction between zinc ions and the aptamer. Significance: The Lab-on-Chip device was systematically evaluated, with particular attention on its detection limits and overall performance and benchmarked against traditional laboratory-scale methods to highlight its effectiveness and potential for real-world applications.