Functionalized vertically aligned ZnO nanorods for application in electrolyte-insulator-semiconductor based pH sensors and label-free immuno-sensors

India-Japan Expert Group Meeting on Biomolecular Electronics & Organic Nanotechnology for Environment Preservation

物理学;生物科学;生态环境科学

Kumar, Narendra^1,3 ; Senapati, Sujata^1 ; Kumar, Satyendra^2,3 ; Kumar, Jitendra^1 ; Panda, Siddhartha^1,2,3

Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur

208016, India^1

Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur

208016, India^2

Samtel Centre for Display Technologies, Indian Institute of Technology Kanpur, Kanpur

208016, India^3

关键词: 3-aminopropyltriethoxysilane;    Electrolyte insulator semiconductors;    Functionalized;    Label-free detection;    Nanorods grown;    PH sensitivity;    Prostate specific antigen;    Vertically aligned;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/704/1/012013/pdf
DOI  :  10.1088/1742-6596/704/1/012013

来源: IOP

【 摘 要 】

Vertically aligned ZnO nanorods were grown on a SiO2/Si surface by optimization of the temperature and atmosphere for annealing of the seed. The seed layer annealed at 500 °C in vacuum provided well separated and uniform seeds which also provided the best condition to get densely packed, uniformly distributed, and vertically aligned nanorods. These nanorods grown on the substrates were used to fabricate electrolyte-insulator-semiconductor (EIS) devices for pH sensing. Etching of ZnO at acidic pH prevents the direct use of nanorods for pH sensing. Therefore, the nanorods functionalised with 3-aminopropyltriethoxysilane (APTES) were utilized for pH sensing and showed the pH sensitivity of 50.1 mV/pH. APTES is also known to be used as a linker to immobilize biomolecules (such as antibodies). The EIS device with APTES functionalized nanorods was used for the label free detection of prostate-specific antigen (PSA). Finally, voltage shifts of 23 mV and 35 mV were observed with PSA concentrations of 1 ng/ml and 100 ng/ml, respectively.