Smartphone-based colorimetric chiral recognition of ibuprofen using aptamers-capped gold nanoparticles.

Sensitive and fast detection of ibuprofen enantiomers is very critical for required routine monitoring and risk assessment of trace pollutants in water samples. Here a simple, rapid and highly sensitive android smartphone application for chiral recognition was developed. Aptamer-capped gold nanoparticles (AuNPs) was demonstrated as an efficient detection platform for (S)-(+)-ibuprofen (S-Ibu) and (R)-(-)-ibuprofen (R-Ibu). Detachment of an enantioselective aptamer from the AuNPs surface and binding with an enantiomer of Ibu lead to AuNPs aggregation, which allows a rapid enantiodiscrimination of Ibu by monitoring the absorbance changes of AuNPs solution in the UV-vis spectrum. Under optimal conditions, the limit of detection for S-Ibu and R-Ibu was 1.24 and 3.91 pg/mL, respectively. These probes showed good chiral recognition ability in mixed samples (i.e. S-Ibu + R-Ibu) and environmental samples. These advantages can be further developed by quantitative measurement with smartphone, which opens new opportunities for on-site detection of trace chiral pollutants in a simple and practical manner.