title: Mechanical desorption of immobilized proteins using carbon dioxide aerosols for reusable biosensors.
abstract: Reusability of a biosensor has recently received considerable attention, and it is closely related with the effective desorption of probe molecules. We present a novel mechanical desorption technique to reuse biosensors by using periodic jets of carbon dioxide (CO2) aerosols (a mixture of solid and gaseous CO2), and demonstrate its feasibility by removing physically adsorbed and covalently bonded fluorescent proteins i.e., Escherichia coli fluorescein isothiocyanate antibody and bovine serum albumin (E. coli FITC-Ab and FITC-BSA) from silicon chips. The proteins on the chip surfaces were measured by fluorescent images before and after applying the aerosols. The removal efficiency of the aerosol treatment was measured for various concentrations (1-20 μg mL(-1)) of E. coli FITC-Ab and FITC-BSA with two different removal cycles (5 and 11 cycles; each cycle: 8s). We observed high removal efficiencies (>93.5% for physically adsorbed Ab and >84.6% for covalently bonded Ab) at 11 cycle aerosol treatment. This CO2 aerosol treatment did not undermine re-functionalization, which was confirmed by the fluorescent images of FITC-Abs for fresh and reused chips. Desorption of the immobilized layers was validated by Fourier transform infrared and X-ray photoelectron spectroscopic analyses. We also conducted an experiment on the regeneration of E. coli sensing chips using this aerosol treatment, and the chips were re-used 5 times successfully. This mechanical desorption technique is a highly effective and novel strategy for reusable biosensors.
authors.affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Renu
authors.initials: R
authors.lastname: Singh
authors.affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Seongkyeol
authors.initials: S
authors.lastname: Hong
authors.affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea; Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea; School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea. Electronic address: jjang@unist.ac.kr.
authors.forename: Jaesung
authors.initials: J
authors.lastname: Jang
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D000818:Animals; D055910:Antibodies, Immobilized / Q000737:chemistry / Q000378:metabolism; D015374:Biosensing Techniques; D002245:Carbon Dioxide / Q000737:chemistry*; D002417:Cattle; D004926:Escherichia coli / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism*; D056951:Photoelectron Spectroscopy; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism; D012825:Silicon / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000336:Aerosols; D055910:Antibodies, Immobilized; D055767:Immobilized Proteins; C039217:fluorescein isothiocyanate bovine serum albumin; D002245:Carbon Dioxide; D012710:Serum Albumin, Bovine; D016650:Fluorescein-5-isothiocyanate; D012825:Silicon
keywords: Antibody; Bovine serum albumin; Carbon dioxide aerosols; Desorption; Reusability