title: A miniaturized nanobiosensor for choline analysis.
abstract: A novel reusable chemiluminescence choline nanobiosensor has been developed using aligned zinc oxide nanorod-films (ZnONR). The chemically fashioned ZnONR were synthesized by hybrid wet chemical route onto glass substrates and used to fabricate a stable chemiluminescent choline biosensor. The biosensor was constructed by co-immobilization of the enzymes choline oxidase and peroxidase. The covalent immobilization of the enzymes on the ZnONR was achieved using 16-phosphonohexadecanoic acid as a cross-linker. The phosphonation of the ZnONR imparted significant stability to the immobilized enzyme as against physisorbed enzyme. A lower value of Michaelis-Menten constant (Km), of 0.062 mM for the covalently coupled enzyme over the physisorbed enzymes facilitated enhanced stability of ZnONR nanobiosensor. The ZnONR-choline biosensor has been investigated over a wide range of choline from 0.0005 mM to 2 mM. Importantly, the recovery of choline in milk samples was close to 99%. Using the developed biosensor, choline was measurable even after 30 days with 60 repeated measurements proving the stability of the sensor (Intraday RSD%=2.83 and Interday RSD%=3.51).
authors: Biosensor Lab., Department of Chemistry, BITS, Pilani -KK Birla Goa Campus, Goa 403726, India.
authors: Souvik
authors: S
authors: Pal
authors: Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India.
authors: Manoj Kumar
authors: MK
authors: Sharma
authors: Acromed Invest AB, Magistratsvagen 10, SE 226 43 Lund, Sweden.
authors: Bengt
authors: B
authors: Danielsson
authors: Physical Electronics and Nanotechnology Division, Department of Science and Technology (ITN) Campus Norrköping, Linköping University, Norrköping SE-60174, Sweden.
authors: Magnus
authors: M
authors: Willander
authors: Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India. Electronic address: rmala@physics.iitd.ernet.in.
authors: Ratnamala
authors: R
authors: Chatterjee
authors: Biosensor Lab., Department of Chemistry, BITS, Pilani -KK Birla Goa Campus, Goa 403726, India. Electronic address: sunil17_bhand@yahoo.com.
authors: Sunil
authors: S
authors: Bhand
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D002794:Choline / Q000032:analysis* / Q000378:metabolism; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D004867:Equipment Design; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry*; D008904:Miniaturization; D043942:Nanotubes / Q000737:chemistry*; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D000429:Alcohol Oxidoreductases; C019888:choline oxidase; D006735:Horseradish Peroxidase; D002794:Choline; D015034:Zinc Oxide
keywords: Chemiluminescence; Choline; Milk; Nanobiosensor; Phosphonation; Zinc oxide nanorod