Enhanced Sensitivity of Gas Sensor Based on Poly(3-hexylthiophene) Thin-Film Transistors for Disease Diagnosis and Environment Monitoring

Autor(es)

Cavallari, Marco R. ^[1] ; Izquierdo, Jose E. E. ^{[1, 2]} ; Braga, Guilherme S. ^{[3, 1]} ; Dirani, Ely A. T. ^{[1, 4]} ; Pereira-da-Silva, Marcelo A. ^{[5, 6]} ; Rodriguez, Estrella F. G. ^[2] ; Fonseca, Fernando J. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Escola Politecn, Dept Engn Sistemas Eletron, BR-05508900 Sao Paulo, SP - Brazil

^[2] ISPJAE, Ctr Invest Microelect CIME, Havana 10800 - Cuba

^[3] Embrapa Instrumentacao, BR-13560970 Sao Carlos, SP - Brazil

^[4] PUC SP, BR-01303050 Sao Paulo, SP - Brazil

^[5] Ctr Univ Cent Paulista UNICEP, BR-13563470 Sao Carlos, SP - Brazil

^[6] Inst Fis Sao Carlos USP, BR-13566590 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SENSORS; v. 15, n. 4, p. 9592-9609, APR 2015.
• Citações Web of Science: 19

Resumo

Electronic devices based on organic thin-film transistors (OTFT) have the potential to supply the demand for portable and low-cost gadgets, mainly as sensors for in situ disease diagnosis and environment monitoring. For that reason, poly(3-hexylthiophene) (P3HT) as the active layer in the widely-used bottom-gate/bottom-contact OTFT structure was deposited over highly-doped silicon substrates covered with thermally-grown oxide to detect vapor-phase compounds. A ten-fold organochloride and ammonia sensitivity compared to bare sensors corroborated the application of this semiconducting polymer in sensors. Furthermore, P3HT TFTs presented approximately three-order higher normalized sensitivity than any chemical sensor addressed herein. The results demonstrate that while TFTs respond linearly at the lowest concentration values herein, chemical sensors present such an operating regime mostly above 2000 ppm. Simultaneous alteration of charge carrier mobility and threshold voltage is responsible for pushing the detection limit down to units of ppm of ammonia, as well as tens of ppm of alcohol or ketones. Nevertheless, P3HT transistors and chemical sensors could compose an electronic nose operated at room temperature for a wide range concentration evaluation (1-10,000 ppm) of gaseous analytes. Targeted analytes include not only biomarkers for diseases, such as uremia, cirrhosis, lung cancer and diabetes, but also gases for environment monitoring in food, cosmetic and microelectronics industries. (AU)

• Processo FAPESP: 08/57706-4 - Instituto Nacional de Eletrônica Orgânica (INEO)
• Beneficiário: Roberto Mendonça Faria
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 11/17184-1 - Estudo e desenvolvimento de sensores químicos para diagnóstico não-invasivo de doenças em seres humanos
• Beneficiário: Ely Antonio Tadeu Dirani
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/19420-0 - Sensores de gás a base de transistores de filmes finos orgânicos
• Beneficiário: Marco Roberto Cavallari
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 09/05589-7 - Estudo e desenvolvimento de LEDs orgânicos, células solares, transistores de filmes finos e sensores baseados em polímeros semicondutores
• Beneficiário: Adnei Melges de Andrade
• Modalidade de apoio: Auxílio à Pesquisa - Regular