title: Protein functionalized carbon nanotubes-based smart lab-on-a-chip.
abstract: A label-free impedimetric lab on a chip (iLOC) is fabricated using protein (bovine serum albumin) and antiapolipoprotein B functionalized carbon nanotubes-nickel oxide (CNT-NiO) nanocomposite for low-density lipoprotein (LDL) detection. The antiapolipoprotein B (AAB) functionalized CNT-NiO microfluidic electrode is assembled with polydimethylsiloxane rectangular microchannels (cross section: 100 × 100 μm). Cytotoxicity of the synthesized CNTs, NiO nanoparticles, and CNT-NiO nanocomposite has been investigated in the presence of lung epithelial cancer A549 cell line using MTT assay. The CNT-NiO nanocomposite shows higher cell viability at a concentration of 6.5 μg/mL compared to those using individual CNTs. The cell viability and proliferation studies reveal that the toxicity increases with increasing CNTs concentration. The X-ray photoelectron spectroscopy studies have been used to quantify the functional groups present on the CNT-NiO electrode surface before and after proteins functionalization. The binding kinetic and electrochemical activities of CNT-NiO based iLOC have been conducted using chronocoulometry and impedance spectroscopic techniques. This iLOC shows excellent sensitivity of 5.37 kΩ (mg/dL)(-1) and a low detection limit of 0.63 mg/dL in a wide concentration range (5-120 mg/dL) of LDL. The binding kinetics of antigen-antibody interaction of LDL molecules reveal a high association rate constant (8.13 M(-1) s(-1)). Thus, this smart nanocomposite (CNT-NiO) based iLOC has improved stability and reproducibility and has implications toward in vivo diagnostics.
authors.affiliation: ‡Department of Biomedical Engineering, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram, Hyderabad, Andhra Pradesh 502205, India.
authors.forename: Md Azahar
authors.initials: MA
authors.lastname: Ali
authors.affiliation: §Special Centre for Nano Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
authors.forename: Pratima R
authors.initials: PR
authors.lastname: Solanki
authors.affiliation: ∥Department of Biotechnology, Delhi Technological University, Main Bawana Road, Delhi 110042, India.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Srivastava
authors.affiliation: §Special Centre for Nano Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
authors.forename: Samer
authors.initials: S
authors.lastname: Singh
authors.forename: Ved V
authors.initials: VV
authors.lastname: Agrawal
authors.affiliation: ‡Department of Biomedical Engineering, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram, Hyderabad, Andhra Pradesh 502205, India.
authors.forename: Renu
authors.initials: R
authors.lastname: John
authors.affiliation: ∥Department of Biotechnology, Delhi Technological University, Main Bawana Road, Delhi 110042, India.
authors.forename: Bansi D
authors.initials: BD
authors.lastname: Malhotra
mesh_terms: D001055:Apolipoproteins B / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004553:Electric Conductivity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D056656:Lab-On-A-Chip Devices; D058726:Nanoconjugates / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D001055:Apolipoproteins B; D058726:Nanoconjugates; D037742:Nanotubes, Carbon
keywords: antiapolipoprotein B; cytotoxicity; impedance; lab-on-a-chip; label-free immunosensor; low density lipoprotein