Sensitivity comparison of vapor trace detection of explosives based on chemo-mechanical sensing with optical detection and capacitive sensing with electronic detection

Strle, Drago (author), Štefane, Bogdan (author), Zupanič, Erik (author), Trifković, Mario (author), Maček, Marijan (author), Jakša, Gregor (author), Kvasić, Ivan (author), Muševič, Igor (author)

The article offers a comparison of the sensitivities for vapour trace detection of Trinitrotoluene (TNT) explosives of two different sensor systems: a chemo-mechanical sensor based on chemically modified Atomic Force Microscope (AFM) cantilevers based on Micro Electro Mechanical System (MEMS) technology with optical detection (CMO), and a miniature system based on capacitive detection of chemically functionalized planar capacitors with interdigitated electrodes with a comb-like structure with electronic detection (CE). In both cases (either CMO or CE), the sensor surfaces are chemically functionalized with a layer of APhS (trimethoxyphenylsilane) molecules, which give the strongest sensor response for TNT. The construction and calibration of a vapour generator is also presented. The measurements of the sensor response to TNT are performed under equal conditions for both systems, and the results show that CE system with ultrasensitive electronics is far superior to optical detection using MEMS. Using CMO system, we can detect 300 molecules of TNT in 10$^{+12}$ molecules of N$_2$ carrier gas, whereas the CE system can detect three molecules of TNT in 10$^{+12}$ molecules of carrier N$_2$.

• Language: English
• Keywords: small capacitance measurements, trinitrotoluene (TNT) vapor trace detection, chemical modifications, gas sensors, micro electro mechanical systems (MEMS) sensors, vapor trace detection
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FE - Faculty of Electrical Engineering; FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2014
• Number of pages: Str. 11467-11491
• Numbering: Vol. 14, iss. 7
• PID: 20.500.12556/RUL-130819
• UDC: 681.5:621.38
• ISSN on article: 1424-8220
• DOI: 10.3390/s140711467
• COBISS.SI-ID: 10678868
• Publication date in RUL: 17.09.2021

Record is a part of a journal

• Title: Sensors
• Shortened title: Sensors
• Publisher: MDPI
• ISSN: 1424-8220
• COBISS.SI-ID: 10176278

Licences

• License: CC BY 3.0, Creative Commons Attribution 3.0 Unported
• Link: https://creativecommons.org/licenses/by/3.0/deed.en
• Description: You are free to reproduce and redistribute the material in any medium or format. You are free to remix, transform, and build upon the material for any purpose, even commercially. You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
• Licensing start date: 01.07.2014

Secondary language

• Language: Slovenian
• Keywords: meritve majhnih kapacitivnosti, detekcija par TNT, kemijska modifikacija, senzorji plinov, MEMS senzorji, detekcija sledi par

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: J7-5497
• Name: Selektivni in hiperobčutljivi mikrokapacitivni senzorski sistem za ciljno detekcijo molekul v atmosferi