A novel fluorescent sensor based on the reuse of a biological matrix for the visual detection of bilirubin

Abstract

Bilirubin (Bil) is crucial for diagnosing jaundice and assessing liver function. Dynamic monitoring of Bil levels helps evaluate disease progression and therapy efficacy. Consequently, developing a method for rapid and accurate detection of bilirubin is essential for clinical diagnosis and therapeutic decision-making. With an emphasis on green and sustainable development, this study employed discarded peels of Dioscorea polystachya (yam) as a carbon source to create green carbon dots (CDs) using a one-step hydrothermal process. The preparation method was uncomplicated and energy-efficient without any specialized treatment. The prepared carbon dots (Dp-CDs) derived from the peel of yam exhibit high water solubility, remarkable photostability, and exceptional biocompatibility. Static quenching, the inner filter effect (IFE) and the aggregation quenching effect among the groups were the main causes of the decrease in fluorescence intensity of Dp-CDs produced by Bil. The fluorescence sensor constructed with the peel of yam presented a favourable response to Bil, with its fluorescence intensity showing a linear relationship with Bil concentration in the range of 0.30 and 200 μM and a detection limit of 0.28 μM. This method effectively identified and detected Bil in serum and urine in clinical practice, achieving recoveries between 95.6 % and 104.5 %. In addition, a paper-based test strip was designed for this experiment, characterized by its portability, economy, and simplicity of visualization. Dp-CDs provide a solid foundation for rapid and accurate Bil detection, which is critical for early diagnosis and illness monitoring.