Ultrasensitive Detection and Wide Dynamic Range Pyrene Quantification Based on Luminescence Restoration of β-Cyclodextrin-Functionalized Silicon Nanowires

This study presents a breakthrough in the detection of polycyclic aromatic hydrocarbons (PAHs), particularly pyrene, recognized as persistent organic pollutants (POPs) with significant bioaccumulation and cancer risks. An optical sensor based on silicon nanowires (Si NWs) is presented, leveraging an approach that combines silane treatment and functionalization with 6-monodeoxy-6-monoamino-beta-cyclodextrin. This method innovatively utilizes the quantum-confinement properties of Si NWs and noncovalent interactions for molecular recognition, enabling highly sensitive pyrene detection in water without prior treatment. The anchoring of beta-CD quenches the optical emission of quantum-confined carriers in Si NWs, whereas the inclusion of pyrene in the receptor cavity restores the luminescence of the system, producing a disruption of luminescence quenching induced by the analyte. The sensor achieves a limit of detection (LoD) of 2 x 10(-4) ppb and a limit of quantification (LoQ) of 0.01 ppb, covering a dynamic range over 6 orders of magnitude. This advancement integrates nanophotonics and supramolecular chemistry, marking a significant leap in environmental monitoring methodologies.