Black phosphorus quantum dots functionalized MXenes as the enhanced dual-mode probe for exosomes sensing

•A biosensor was constructed for detection of exosomes by utilizing dual-modality probe of MXenes-BPQDs.•BPQDs as coreactant of Ru(dcbpy)32+ was used to prepare self-enhanced BPQDs-Ru(dcbpy)32+ composites with strong ECL signal.•MXenes-BPQDs with excellent photothermal properties were for the first time used as photothermal probe for bioanalysis.•This work used ECL/temperature dual signals to detect exosomes, making results more convincing. Exosomes are nanoscale extracellular vesicles and have proven to be an effective biomarker for early cancer diagnosis. In this work, an ECL and photothermal dual-mode biosensor was fabricated for exosomes detection by utilizing emerging materials black phosphorous quantum dots (BPQDs) and MXenes as signal amplifier. To be specific, BPQDs can catalyze the oxidization of Ru(dcbpy)32+ and was for the first time used as coreactant, the prepared self-enhanced Ru(dcbpy)32+@BPQDs ECL system can produce a strong ECL signal by reducing energy loss and shortening electron transfer distance. MXenes possess large specific surface area and outstanding conductivity, which was employed as supporter to increase the immobilization amount of Ru(dcbpy)32+ and BPQDs, further enhanced ECL signal. Furthermore, BPQDs and MXenes both have excellent photothermal effect, which were dexterously used as thermal convertor device to develop photothermal biosensor for exosomes analysis. This work innovatively employed a dual-modality probe of MXenes-BPQDs to establish biosensor, which not only enriched the application of MXenes and BPQDs in biodetection but also provided an effective and reliable method for exosomes detection.