P and N type copper phthalocyanines as effective semiconductors in organic thin-film transistor based DNA biosensors at elevated temperaturesElectronic supplementary information (ESI) available: Additional OTFT data for F16-CuPc devices deposited at T = 25 °C and 140 °C characterized at varied temperatures in air and vacuum. See DOI: 10.1039/c8ra08829b

• Main Authors: Boileau, Nicholas T, Melville, Owen A, Mirka, Brendan, Cranston, Rosemary, Lessard, Benoît H
• Format: Journal Article
• Published: 15.01.2019
• ISSN: 2046-2069
• DOI: 10.1039/c8ra08829b

Many health-related diagnostics are expensive, time consuming and invasive. Organic thin film transistor (OTFT) based devices show promise to enable rapid, low cost diagnostics that are an important aspect to enabling increased access and availability to healthcare. Here, we describe OTFTs based upon two structurally similar P (copper phthalocyanine - CuPc) and N (hexdecafluoro copper phthalocyanine - F 16 -CuPc) type semiconductor materials, and demonstrate their potential for use as both temperature and DNA sensors. Bottom gate bottom contact (BGBC) OTFTs with either CuPc or F 16 -CuPc semiconducting layers were characterized within a temperature range of 25 °C to 90 °C in both air and under vacuum. CuPc devices showed small positive shifts in threshold voltage ( V T ) in air and significant linear increases in mobility with increasing temperature. F 16 -CuPc devices showed large negative shifts in V T in air and linear increases in mobility under the same conditions. Similar OTFTs were exposed to DNA in different hybridization states and both series of devices showed positive V T increases upon DNA exposure, with a larger response to single stranded DNA. The N-type F 16 -CuPc devices showed a much greater sensing response than the P-type CuPc. These findings illustrate the use of these materials, especially the N-type semiconductor, as both temperature and DNA sensors and further elucidate the mechanism of DNA sensing in OTFTs. This study illustrates the use of an N-type semiconductor, in both temperature and DNA sensors and further elucidates the mechanism of DNA sensing in OTFTs.