Rice husk assisted carbon quantum dots synthesis for amoxicillin sensing

Abstract

Recently, the green method synthesized biosensors have been used for numerous environmental and biomedical applications, especially nanomaterials-based biosensors. Herein, novel, environmentally friendly, and water-soluble carbon quantum dots (CQDs) have been synthesized from the readily available green source (rice husk) without any ionic or covalent modifications via a one-pot synthesis method. The CQDs were characterized using UV–visible spectroscopy, SEM, XPS, and Fourier transform infrared spectroscopy, and their optical properties were determined. The stability of the synthesized CQDs was determined under the effect of pH, time, and temperature and on different excitation wavelengths. The band gap energy was calculated using Tauc’s equation with the energy of 3.2 eV, which indicated that the CQDs are fluorescent, and the linear range and association constant were determined by the Stern- Volmer relation and Bensi- Hildebrand equation, respectively. The photophysical studies indicated the strong fluorescence emission with excitation dependent behaviour and the CQDs relation with amoxicillin. Hence, in this study, the sensor producing remarkable sensitivity of antibiotics with a detection limit in the nM range was proposed.

Keywords

• Sensor
• Amoxicillin
• Green synthesis
• Fluorescence spectroscopy
• Carbon dots