▎ 摘　　要

A selective, sensitive, and safe nanoprobe was developed for detection of the endocrine disruptors; o- and p-nitrophenols (ONP and PNP, respectively) based on blue luminescent graphene quantum dots (GQDs). The two isomers efficiently quench the intense fluorescence of GQDs (lambda(ex)/lambda(em) of 350/440 nm). A thorough study evidenced that the fluorescence quenching by ONP and PNP originates from inner filter effect and dynamic quenching. Additionally, the quenching sphere of action contributes to the quenching mechanisms at high concentrations of ONP. The fluorescence nanoprobe shows excellent linearity over wide dynamic ranges of 0.30-60.0 and 0.20-40.0 mu g/mL with limits of quantification of 0.23 and 0.11 mu g/mL and limits of detection of 0.07 and 0.03 mu g/mL for ONP and PNP, respectively. The sensing system was fully validated and successfully used for detection of ONP and PNP in real samples from tap, river, and rainwaters showing excellent selectivity and recovery (98.5-102.0%). A smartphone image processing-assisted paper-based analytical device has been also designed employing a free software as an easily handled and portable device for fast in-field analysis of environmental waters. Moreover, ImageJ software coupled to a computer was applied for image processing to validate the newly adopted smartphone powered software. Statistical comparison of the data obtained by the two software programs showed no significant difference. This platform is very important and interesting specially for the developing countries lacking the facilities and infrastructure including advanced analytical laboratories and instruments. Such tactic allows these countries to keep pace with the increasing global requirements for environmental and human protection.