Enhanced Photoelectrochemical Detection of an Analyte Triggered by Its Concentration by a Singlet Oxygen-Generating Fluoro Photosensitizer.
Adrian BlidarStanislav TrashinErik N CarriónSergiu M GorunCecilia CristeaKarolien De WaelPublished in: ACS sensors (2020)
The use of a photocatalyst (photosensitizer) which produces singlet oxygen instead of enzymes for oxidizing analytes creates opportunities for designing cost-efficient and sensitive photoelectrochemical sensors. We report that perfluoroisopropyl-substituted zinc phthalocyanine (F64PcZn) interacts specifically with a complex phenolic compound, the antibiotic rifampicin (RIF), but not with hydroquinone or another complex phenolic compound, the antibiotic doxycycline. The specificity is imparted by the selective preconcentration of RIF in the photocatalytic layer, as revealed by electrochemical and optical measurements, complemented by molecular modeling that confirms the important role of a hydrophobic cavity formed by the iso-perfluoropropyl groups of the photocatalyst. The preconcentration effect favorably enhances the RIF photoelectrochemical detection limit as well as sensitivity to nanomolar (ppb) concentrations, LOD = 7 nM (6 ppb) and 2.8 A·M-1·cm-2, respectively. The selectivity to RIF, retained in the photosensitizer layer, is further enhanced by the selective removal of all unretained phenols via simple washing of the electrodes with pure buffer. The utility of the sensor for analyzing municipal wastewater was demonstrated. This first demonstration of enhanced selectivity and sensitivity due to intrinsic interactions of a molecular photocatalyst (photosensitizer) with an analyte, without use of a biorecognition element, may allow the design of related, robust, simple, and viable sensors.
Keyphrases
- photodynamic therapy
- visible light
- pulmonary tuberculosis
- label free
- ionic liquid
- mycobacterium tuberculosis
- wastewater treatment
- highly efficient
- loop mediated isothermal amplification
- low cost
- real time pcr
- solid phase extraction
- gold nanoparticles
- high resolution
- structural basis
- positron emission tomography
- computed tomography
- sensitive detection
- binding protein
- risk assessment
- carbon nanotubes
- oxide nanoparticles
- drug induced
- mass spectrometry