Development of carbon dots sensor dipstick from sugarcane bagasse agricultural waste toward all-cellulose-derived tetracycline sensor

Tetracycline antibiotic has been widely used in veterinary and aquafarming medicines to prevent and treat infectious diseases. However, the overall use of tetracycline results in its accumulation in the organism organs, which then migrates to food and eventually increases the risk of developing various diseases. As one of the most well-known contaminants, sugarcane bagasse (SCB) agricultural waste has been a serious problem worldwide. In order to develop luminous carbon dots doped with nitrogen (NCDs), a simple and environmentally friendly approach was devised to reprocess sugarcane bagasse agricultural waste. A passivating agent, ammonium hydroxide (NH4OH), was used during the hydrothermal carbonization of NCDs in a single-pot procedure. Carbon dots nanoparticles (5–8 nm) embedded in cellulose paper assay were used to prepare the testing strip. With an emission wavelength of 447 nm upon excitation at 355 nm and, NCDs displayed a quantum yield (QY) of up to 24.81%. As a result of the inner filter effect (IFE), the fluorescence of NCDs was clearly quenched by tetracycline, demonstrating their exceptional tetracycline selectivity. The detection limit was set in the concentration range of 0–110 μM. Tetracycline is detected and measured using the current cellulose paper strip, which contains a fluorescent signal that could be turned off to eliminate the signal. The fluorescence quenching feature of cellulose carbon dots in the existence of tetracycline affects the fluorescence activity of the paper strip assay.