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Molecularly Imprinted Sol-Gel for TNT Detection with Optical Micro-Ring Resonator Sensor Chips

: Eisner, Ludmila; Wilhelm, Isabel; Flachenecker, Günter; Hürttlen, Jürgen; Schade, Wolfgang

Fulltext urn:nbn:de:0011-n-5592621 (1.4 MByte PDF)
MD5 Fingerprint: 1ae47ec468dca2179bdca51d04778911
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Created on: 27.9.2019

Sensors. Online journal 19 (2019), No.18, Art. 3909, 12 pp.
ISSN: 1424-8220
ISSN: 1424-8239
ISSN: 1424-3210
Journal Article, Electronic Publication
Fraunhofer ICT ()
Fraunhofer HHI ()
micro-ring resonator; molecularly imprinted sol-gel; evanescent field sensor; explosives

A sensor for trinitrotoluene (TNT) detection was developed by using a combination of optical micro-ring technology and a receptor coating based on molecularly imprinted sol-gel layers. Two techniques for deposition of receptor layers were compared: Airbrush technology and electrospray ionization. A concentration of less than 5 ppb for TNT in the gas-phase, using electrospray deposition of the receptor layer, was detected. The cross-sensitivities to organic substances and further nitro-based explosives were compared. As a result, the sensitivity to TNT is about one order of magnitude higher in comparison to the explosives 2,4-dinitrotoluene (DNT) or 1,3-dinitrobenzene (DNB) and about four orders of magnitude higher than the organic substances phenol, ethanol, and acetone. The signal response of the sensor is fast, and the compact sensor design enables the deposition of different receptor layers on multiple optical micro-rings on one chip, which allows a more precise analysis and reduction of side effects and false alarms.