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Publication Metadata only Electrochemically functionalized single-walled carbon nanotubes for ultrasensitive detection of BTEX vapors(2021-07-15) Tapan Sarkar; Sira Srinives; University of California, Riverside; Mahidol University; Guru Gobind Singh Indraprastha UniversitySingle-walled carbon nanotubes (SWNTs) have been functionalized electrochemically with porphyrin and were employed as the channel to fabricate the chemical field-effect transistor. Tetraphenylporphyrin was chosen for functionalization purpose... response for all analytes starting from 1.25 ppm to 15 ppm of concentration. A sub-ppm limit of detection was also observed. The systematic study of field effect transistor (FET) measurements indicates that the sensing mechanism is dominatedPublication Metadata only Nanothin polyaniline film for highly sensitive chemiresistive gas sensing(2013-06-01) Sira Srinives; Tapan Sarkar; Ashok Mulchandani; University of California, Riverside; Mahidol UniversityThis study developed a facile technique for site-specific synthesis of nanometer-thick polyaniline (PANI) film for fabrication of field-effect transistor/chemiresistor sensors. The nanothin film had a thickness of 9-20nm and was of carpet-likePublication Metadata only Calixarene-functionalized single-walled carbon nanotubes for sensitive detection of volatile amines(2018-09-01) Tapan Sarkar; P. Muhamed Ashraf; Sira Srinives; Ashok Mulchandani; University of California, Riverside; Mahidol University; Guru Gobind Singh Indraprastha Universityand ∼0.4 ppm for NH3, TMA and DMA respectively. Further, the field effect transistor analyses indicated that the sensing mechanism of the SWCNT-calixarene hybrid is dominated by the electrostatic gating effect. The sensing capability of the hybrid at lowPublication Metadata only Single-walled Carbon Nanotube-Calixarene Based Chemiresistor for Volatile Organic Compounds(2018-09-01) Tapan Sarkar; Sira Srinives; Armando Rodriquez; Ashok Mulchandani; University of California, Riverside; Mahidol University; Guru Gobind Singh Indraprastha UniversityAdministration (OSHA) permissible exposure limit (PEL) except for benzene. A mechanistic study for BTEX was performed via field-effect transistor measurements, and this suggested that the sensing mechanism is dominated by an electrostatic gating effect. In our... beneficial effects: (a) The use of SWCNT eliminates the conductivity issue, and this enables low-power chemiresistive sensing; (b) the excellent affinity of calixarenes for certain analytes improves sensitivity. The hybrid material was fabricated by solvent