A new approach for optical chemical sensor based on molecularly imprinted polymer (MIP) and localizedsurface plasmon resonance (LSPR) in plastic optical fibers (POFs), for the selective detection and analysisof 2,4,6-trinitrotoluene (TNT) in aqueous solution, has been developed. LSPR is excited in five-branchedgold nanostars (GNS), suspended in an MIP specific for TNT (GNS-MIP), which assures the selectivity. Thissensing layer has been deposited directly on two different POF platforms, i.e. tapered and not-taperedPOF. Both sensors show better performance than a similar one previously proposed, in which the surfaceplasmon resonance (SPR) was excited in a thin gold layer at the surface of the POF in contact with the MIPlayer (specific for TNT). In particular, in the sensor with a GNS-MIP sensing layer on the not-tapered POFthe sensitivity was 8.5 × 104nm/M, three times higher than in the gold layer sensor. In the sensor withGNS-MIP sensing layer on tapered POF the sensitivity increases further up to 8.3 × 105nm/M, thirty timeshigher than in the gold layer sensor, because the penetration depth of the evanescent field increases andthe number of the interaction sites of TNT, in the MIP involved in the generation of the signal, increasesaccordingly.
|Titolo:||Sensitive detection of 2,4,6-trinitrotoluene by tridimensional monitoring of molecularly imprinted polymer with optical fiber and five-branched gold nanostars|
|Data di pubblicazione:||2015|
|Appare nelle tipologie:||1.1 Articolo in rivista|