MXene-based fluorescent aptasensors: advances and prospects in diagnostics and environmental monitoring

Abstract

MXene-based fluorescent aptasensors leverage the synergistic integration of the intrinsic physicochemical properties of MXenes, including tunable surface chemistry, broad-spectrum optical absorption, and superior fluorescence quenching efficiency, with the molecular recognition capabilities and strong binding affinity of aptamers. These two-dimensional transition metal carbides and nitrides efficiently suppress background fluorescence in dye-labeled aptamer systems through electrostatic interactions and π–π stacking. In the absence of the target analyte, the aptamers adsorb onto the MXene surface, facilitating non-radiative energy transfer and thereby suppressing the signal. Upon specific target recognition, a conformational rearrangement of the aptamer reduces its surface affinity, leading to desorption and subsequent fluorescence recovery via a target-induced “signal-on” mechanism. Such platforms demonstrate ultra-low detection limits, excellent selectivity, and modular adaptability for the detection of a broad spectrum of analytes, including clinical biomarkers, pathogenic microorganisms, environmental toxins, and heavy metal ions. This comprehensive review systematically summarises the mechanistic foundations of MXene–aptamer interactions, recent advancements in analytical applications, and emerging directions for translational development in biomedical diagnostics and environmental monitoring.