Applications of Optical Method As an Effective Platform for Progesterone Sensing Using Carbon Dots and Graphene Oxide

Abstract

Today, ‘Hormonal imbalance’ is a significant concern worldwide that lead to various types of complications in human body. For instance, abnormal levels of steroid hormones, such as progesterone are associated with irregular or absent menstrual periods, reproductive disorders, infertility, cardiovascular diseases, and cancer. Nowadays, progesterone is being excessively consumed as oral contraceptives, menopausal hormone therapy and treating infertility, resulting into the deleterious effects due to its endocrine disrupting activity. Furthermore, its presence as a potent endocrine disruptor in surface or environmental waters and various daily use products is another concern. Therefore, monitoring progesterone hormone is vital in environmental samples because of the adverse effects on reproductive health and causing hormonal imbalance. Herein, we have developed optical photoluminescence (PL) method implementing carbon dots (CDs) and graphene oxide (GO) based fluorescence resonance energy transfer (FRET) mechanism for progesterone hormone sensing. In this method, firstly progesterone-specific antibodies are covalently functionalized to CDs whose fluorescence has been quenched (turn off) by adding GO. However, the presence of progesterone increases the distance between donor and acceptor moieties and turns-on the fluorescence by displacing GO off the surface of CDs which in turn substantially reduces the FRET efficiency. Various optimization steps have been performed under control experiments to tune the fluorescence of CDs and the concentration of graphene oxide for maximum efficiency. In conclusion, a linear relationship is achieved in between PL intensity and different progesterone concentrations (10-900 nM) with 13.8 nM detection limits (R2=0.974). The structural and morphological analysis (XPS, and FT-IR) revealed the structural and surface functionalities of CDs. Finally, the potential of the developed biosensor has been explored in water matrices.