Controlled deposition of functionalized silica coated zinc oxide nano-assemblies at the air/water interface for blood cancer detection

• Stable and controlled deposition of Am-Si@ZnO nano-assemblies using LB technique.
• Uniform monolayer deposition of the Am-Si@ZnO LB film within the nanometer range.
• Am-Si@ZnO LB film shows enhanced electrochemical properties.
• Fabricated nucleic acid sensor is ultrasensitive (1 × 10−16 M) for CML detection.
• Validation with clinical samples of CML positive patients shows its potential for clinical diagnosis.

We report results of the studies relating to controlled deposition of the amino-functionalized silica-coated zinc oxide (Am-Si@ZnO) nano-assemblies onto an indium tin oxide (ITO) coated glass substrate using Langmuir-Blodgett (LB) technique. The monolayers have been deposited by transferring the spread solution of Am-Si@ZnO stearic acid prepared in chloroform at the air-water interface, at optimized pressure (16 mN/m), concentration (10 mg/ml) and temperature (23 °C). The high-resolution transmission electron microscopic studies of the Am-Si@ZnO nanocomposite reveal that the nanoparticles have a microscopic structure comprising of hexagonal assemblies of ZnO with typical dimensions of 30 nm. The surface morphology of the LB multilayer observed by scanning electron microscopy shows uniform surface of the Am-Si@ZnO film in the nanometer range (<80 nm). These electrodes have been utilized for chronic myelogenous leukemia (CML) detection by covalently immobilizing the amino-terminated oligonucleotide probe sequence via glutaraldehyde as a crosslinker. The response studies of these fabricated electrodes carried out using electrochemical impedance spectroscopy show that this Am-Si@ZnO LB film based nucleic acid sensor exhibits a linear response to complementary DNA (10−6–10−16 M) with a detection limit of 1 × 10−16 M. This fabricated platform is validated with clinical samples of CML positive patients and the results demonstrate its immense potential for clinical diagnosis.

Controlled deposition of functionalized silica coated zinc oxide nano-assemblies at the air/water interface for label free electrochemical detection of chronic myelogenous leukemia.Figure optionsDownload as PowerPoint slide