Label-Free Vapor Selectivity in Poly(p-Phenylene Oxide) Photonic Crystal Sensors.
The lack of sensors for low cost, extensive, and continuous detection of vapor pollutants is a serious concern for health and safety in industrialized urban areas. Colorimetric sensors, such as distributed Bragg reflectors made of polymers, could achieve this task thanks to their low cost and easy signal transduction but are typically affected by low vapor permeability and lack of selectivity without chemical labeling. Here we demonstrate all-polymer Bragg multilayers for label-free selective detection of organic volatile compounds. The system exploits the ability of amorphous poly(p-phenylene oxide), PPO, to uptake large amount of guest molecules and to form cocrystalline phases with distinct optical properties. Bragg stacks embedding PPO active layers show selective colorimetric response to vapors of carbon tetrachloride and aromatic homologues, which can be revealed by the naked eye.
Energy Research Institute at NTU (ERI@AN), Interdisciplinary Graduate School, Nanyang Technological University , Singapore 639798.|Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Genova , 16126 Genova, Italy.
Paola
P
Lova
Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Genova , 16126 Genova, Italy.
Chiara
C
Bastianini
Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Genova , 16126 Genova, Italy.
Paolo
P
Giusto
Dipartimento di Fisica, Università degli Studi di Pavia , 27100 Pavia, Italy.
Maddalena
M
Patrini
Dipartimento di Chimica e Biologia, Università di Salerno , 84084 Salerno, Italy.
Paola
P
Rizzo
Dipartimento di Chimica e Biologia, Università di Salerno , 84084 Salerno, Italy.
Gaetano
G
Guerra
Istituto per la Microelettronica e Microsistemi, Consiglio Nazionale delle Ricerche , 95121 Napoli, Italy.
Mario
M
Iodice
Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University , Singapore 637371.
Cesare
C
Soci
Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Genova , 16126 Genova, Italy.
Davide
D
Comoretto
colorimetric sensor; label-free selectivity; photonic crystal sensors; poly(p-phenylene oxide); vapor detection