Briefly, AZ5214 photoresist (PR) was used to fabricate a pattern on a SiO2 wafer. The wafer was dipped into octacyltrichlorosilane (OTS) solution (OTS:hexane = 1:500) for 7 min. The wafer was rinsed with hexane, acetone, and ethanol to remove the PR patterns. The OTS-patterned substrate was incubated in swCNT solution (0.02 mg/ml in 1,2-dichlorobenzene) for 30 s, and CNTs were specifically absorbed to the substrate. Afterward, Pd/Au (10/30 nm) electrodes were fabricated and passivated using PR to protect them from contacting the solution. The Drosophila OBP-derived peptide (TKCVSLMAGTVNKKGEFFFF) was synthesized with purity higher than 90% by Peptron (Korea). The peptide was diluted at 1 μg mL-1 in distilled water and stored at −20 °C. For the immobilization of the peptide, 1.5 μL of peptide solution was placed on the CNT channel and incubated for 4 h at room temperature. After the immobilization process, unbound peptides were washed out 2–3 times with distilled water. Atomic force microscopy (AFM) system (MFP-3D, Asylum Research, USA) was used to analyze the immobilization of the peptide. The pristine CNT channel was imaged at a scan rate of 0.2 Hz. After the peptide immobilization, the CNT channel was imaged again at 0.05
Briefly, AZ5214 photoresist (PR) was used to fabricate a pattern on a SiO2 wafer. The wafer was dipped into octacyltrichlorosilane (OTS) solution (OTS:hexane = 1:500) for 7 min. The wafer was rinsed with hexane, acetone, and ethanol to remove the PR patterns. The OTS-patterned substrate was incubated in swCNT solution (0.02 mg/ml in 1,2-dichlorobenzene) for 30 s, and CNTs were specifically absorbed to the substrate. Afterward, Pd/Au (10/30 nm) electrodes were fabricated and passivated using PR to protect them from contacting the solution. The Drosophila OBP-derived peptide (TKCVSLMAGTVNKKGEFFFF) was synthesized with purity higher than 90% by Peptron (Korea). The peptide was diluted at 1 μg mL-1 in distilled water and stored at −20 °C. For the immobilization of the peptide, 1.5 μL of peptide solution was placed on the CNT channel and incubated for 4 h at room temperature. After the immobilization process, unbound peptides were washed out 2–3 times with distilled water. Atomic force microscopy (AFM) system (MFP-3D, Asylum Research, USA) was used to analyze the immobilization of the peptide. The pristine CNT channel was imaged at a scan rate of 0.2 Hz. After the peptide immobilization, the CNT channel was imaged again at 0.05