Fabrication of fluorescence sensor array for discrimination subtypes of aminoglycosides leveraging MOF-based inhibition reactions and thiol-response metal nanoclusters.

Detection and discrimination aminoglycoside (AG) subtypes are crucial, which remains a formidable challenge. In this study, a sensor array for differentiating of AGs was developed. This was achieved by integrating the inhibitory effect of AGs on the acetylcholinesterase (AChE)-like activities of Al3+ decorated MOF-808 (MOF-808-Al) and the thiol-response fluorescence of metal nanoclusters (NCs). MOF-808-Al exhibited AChE-like activities, which catalyzed the decomposition of AChE into thiocholine, ascribed to the synergistic effect of metal-OH and Lewis acid sites. Thiocholine quenched the green fluorescence of Au NCs by forming Au-S bonds. In contrast, the blue-emissive Cu NCs showed high resistance to thiocholine. AGs inhibited the AChE-like activities of MOF-808-Al through forming stronger interactions with metal and Lewis acid sites compared to acetylthiocholine. By analyzing the fluorescence changes of green- and blue-emissive metal NCs, a sensor array was constructed, and five subtypes of AGs were quantitatively detected and discriminated, with a limit of detection and limit of quantitation of 11.2 μM and 12.9 μM, respectively. The discrimination of mixed AGs in both buffer solutions and practical samples was also successfully achieved, indicating the great potential for practical applications.