Construction of a hydrophobic-hydrophilic open-droplet microfluidic chemosensor towards colorimetric/spectrophotometric recognition of quetiapine fumarate: a cost-benefit method for biomedical analysis using a smartphone

Quetiapine fumarate (QF) is used to treat a number of mental/emotional diseases, including schizophrenia, bipolar disorder, and abrupt bouts of mania or depression linked to bipolar disorder. This antipsychotic medicine can be deadly if an overdose is given to a person. Therefore, the sensitive identification of QF in bodily fluids is very important. In this study, an innovative low-cost colorimetric chemosensor based on silver nanoprism transfiguration in a phosphate-buffered saline (PBS)/Cl^- matrix was developed and successfully tested for the recognition of QF in human-exhaled breath condensate. Using this non-invasive colorimetric chemosensor, a broad linearity range of 0.001-1000 μM and a low limit of quantification of 0.001 μM for QF were attained. Notably, the proposed optical chemosensor is capable of detecting QF from a minimum amount of sample [500 μM in PBS and 0.001 μM in exhaled breath condensate] in the first few seconds of reaction by the naked eye. So, a rapid colorimetric assay for the on-site analysis of QF was developed and validated. Moreover, for the first time, a semi-analytical method was introduced that can provide a rough estimation of the QF concentration. This colorimetric system was, for the first time, integrated in an optimized microfluidic paper-based colorimetric device (μPCD), promising the development of an engineered colorimetric opto-sensor toward real-time and therapeutic drug monitoring (TDM) assay of drugs in real-world samples.