A Green and Simple Carbon-dot-based Fluorescent Probe for Selective and Sensitive Detection of Ranitidine Hydrochloride

Herein, a novel fluorescent probe was designed and synthesized for the selective and sensitive detection of ranitidine hydrochloride based on the quenched fluorescence signal of carbon dots (CDs). The one-step hydrothermal treatment of Urtica dioica extract was used to prepare CDs. The as-synthesized CDs exhibited excellent water dispersibility and had a blue color under UV light irradiation (365 nm) with 12.49% of quantum yield (QY). The structural and optical properties of CDs were investigated using UV-Vis spectrophotometer, transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) spectroscopy. The as-synthesized CDs were used as a simple, sensitive, and inexpensive probe for the detection of ranitidine hydrochloride in pharmaceutical samples. The absorption spectrum of ranitidine overlapped with the excitation spectrum of CDs and the fluorescence intensity of CDs effectively decreased with the increase of ranitidine concentration due to the inner filter effect (IFE). A fluorometric assay was formed based on these findings that had a linear response in the ranitidine hydrochloride concentration range of 0.167-14.03 μg ml-1 with a detection limit as low as 0.081 μg ml-1. This new sensing assay was green and had beneficial features such as simplicity, rapidity, inexpensiveness, and ease of operation without the need for further modification. Using the suggested method, ranitidine hydrochloride was successfully measured in the pharmaceutical preparations.