Detection and Quantification of Urine Albumin Using a Miniature Colorimetric Sensor Consisting of UVC LEDs and CsPbBr3 Quantum Dot Color Converters

Albumin, a globular protein, is commonly used as an indicator of kidney damage when conducting invasive blood tests and non-invasive urine tests. Moreover, chemical methods that convert ultraviolet light to visible light require additional labeling steps to distinguish albumin from other proteins. In this study, to address labeling issue, a miniature colorimetric sensor (MCS) including the light source using a flip-chip (FC) ultraviolet C light emission diode (UVC-LED) and a green CsPbBr
₃
quantum dot (QD) film emitting at 530 nm for converting the transmitting ultraviolet light through bovine serum albumin (BSA) and human serum albumin (HSA) to green fluorescence was developed. The proposed sensor detected BSA and HSA at a concentration range of 0.05 to 4.00 mg/mL, with coefficients of determination(R
²
) of 0.9822 and 0.9850, limits of detection of 0.61 mg/mL and 0.56 mg/mL, and limits of quantitation of 2.02 mg/mL and 1.86 mg/mL, respectively. Additionally, the portable FC UVC-LEDs MCS offers reduced size and weight while maintaining detection linearity, compared to the conventional spectrometer. The fluorescence detection sensor using UVC-LED emitters and CsPbBr
₃
QD film color convertors proposed herein provides an accurate, label-free, instantaneous and non-invasive real-time monitoring and quantification tool for albumin-associated disease diagnosis.