Suppression of photo-induced electron transfer of alcaftadine for its photoluminescence detection in aqueous humor

[Display omitted] •For the first time ever, green fluorescence method for determination of alcaftadine.•Determination of the studied drug in aqueous humor.•Direct application of samples without pretreatment or extraction steps.•The method presented a new alternative for bioavailability studies of alcaftadine. A green, facile and selective fluorimetric approach was described for estimating alcaftadine (ALC) in its pure form, eye drop formulation, and artificial aqueous humor for the first time. The developed approach depends on the suppression of the photoinduced electron transfer (PET) impact of the lone pair of the N-atom of the piperidine ring of ALC. PET suppression was attained by using 0.3 M acetic acid as an efficient protonating agent. By virtue of this phenomenon, ALC was quantified from 50 to 400 ng mL−1 with a very low detection and quantitation limit of 2.22 and 6.72 ng mL−1, respectively. Additionally, the presented method was employed for estimating the target drug in artificial aqueous humor and observably there is no significant interference from the aqueous humor matrix.