Novel fluorescence and smartphone-assisted colorimetric sensing platform based on ionic liquid carbon dots for rapid detection of amylase in urine

Changes in amylase (AMY) concentration in urine serve a vital function in monitoring human health. However, the development of non-destructive, sensitive, and real-time assays for AMY concentration still faces serious challenges. In this study, a novel fluorescence/smartphone imaging colorimetric dual-mode sensing platform based on ionic liquid carbon dots (IL-CDs) was designed for the first time for assessing AMY concentration in urine. The obtained IL-CDs exhibited high sensitivity, good selectivity, and excellent stability. AMY can significantly decrease the fluorescence intensity through static quenching, enabling direct AMY concentration monitoring. Significantly, the proposed method was extended to the measurement of AMY in the urine samples with good spiked recoveries (96.98–103.81 %) as well as high accuracy. Furthermore, a smartphone-dependent detection method was developed after exploring the association between IL-CDs (G/(R + B)) fluorescence intensity at different concentrations of AMY, which simplified the AMY detection process. Through the combination of fluorescence and smartphone imaging colorimetry, it not only eliminated the damage to the human body during the detection process, but also realized the direct detection of AMY. The present method provided a fast and reliable new idea for monitoring human health.