Straightforward paper sensors for the detection of SSRI drugs using tyrosine functionalized GQDs: Fluorescence 'turn-off' turns on the crucial dosage monitoring.

All socioeconomic classes are impacted by the COVID-19 epidemic, with stress being one of the biggest symptoms causing indigestion, breathlessness, heart disease, obesity, and many more. The most commonly used selective serotonin reuptake inhibitors (SSRIs) drugs include, escitalopram, sertraline, paroxetine, and fluoxetine are provided by doctors. If the medicines are not taken in the recommended dosage, at the correct intervals, which can occasionally be fatal because persons with depression are susceptible to mood fluctuations. There are no appropriate ways to monitor high dosages in clinical laboratories, the requirement for simple, novel material with cutting-edge technology to do so is essential. Herein, we report the application of a single fluorescent probe, Tyrosine-GQDs for the detection of SSRI drugs. Upon addition of SSRI drugs into the Tyrosine-GQDs, the fluorescence emission intensity of Tyrosine-GQDs decreased due to the complex formation through H-bonding which is evidenced by the rise of new peaks in fluorescence spectra and lifetime measurements. The calculated detection limit proves that the designed nanoprobe is highly sensitive and selective towards escitalopram, sertraline, paroxetine, and fluoxetine are 0.13 × 10−6 M, 0.15 × 10−6 M, 0.07 × 10−6 M, and 0.07 × 10−6 M, respectively. A paper-based fluorescent sensor is fabricated using the designed probe which is efficient in the detection of the dosage of SSRI drugs. [Display omitted] • Tyrosine-GQDs are employed for the spectrophotometric detection of SSRI drugs. • The limit of detection for the SSRI drugs is quantified in sub-micromolar concentration. • The effect of interference shows that the complex formed between the Tyrosine-GQDs and drugs is highly stable. • The H-bond formation between the drugs and Tyrosine-GQDs dominates the mechanism responsible for the fluorescence quenching. • The fluorescent paper sensor is effective in determining the SSRI drugs. [ABSTRACT FROM AUTHOR]