title: Flow injection based microfluidic device with carbon nanotube electrode for rapid salbutamol detection.
abstract: A microfabicated flow injection device has been developed for in-channel electrochemical detection (ECD) of a beta-agonist, namely salbutamol. The microfluidic system consists of PDMS (polydimethylsiloxane) microchannel and electrochemical electrodes formed on glass substrate. The carbon nanotube (CNT) on gold layer as working electrode, silver as reference electrode and platinum as auxiliary electrode were deposited on a glass substrate. Silver, platinum, gold and stainless steel catalyst layers were coated by DC-sputtering. CNTs were then grown on the glass substance by thermal chemical vapor deposition (CVD) with gravity effect and water-assisted etching. 100-microm-deep and 500-microm-wide PDMS microchannels fabricated by SU-8 molding and casting were then bonded on glass substrate by oxygen plasma treatment. Flow injection and ECD of salbutamol was performed with the amperometric detection mode for in-channel detection of salbutamol. The influences of flow rate, injection volume, and detection potential on the response of current signal were optimized. Analytical characteristics, such as sensitivity, repeatability and dynamic range have been evaluated. Fast and highly sensitive detection of salbutamol have been achieved. Thus, the proposed combination of the efficient CNT electrode and miniaturized lab-on-a-chip is a powerful platform for beta-agonists detection.
authors.affiliation: Nanoelectronics and MEMS Laboratory, National Electronics and Computer Technology Center, Pathumthani 12120, Thailand.
authors.forename: Chanpen
authors.initials: C
authors.lastname: Karuwan
authors.forename: Anurat
authors.initials: A
authors.lastname: Wisitsoraat
authors.forename: Thitima
authors.initials: T
authors.lastname: Maturos
authors.forename: Disayut
authors.initials: D
authors.lastname: Phokharatkul
authors.forename: Assawapong
authors.initials: A
authors.lastname: Sappat
authors.forename: Kata
authors.initials: K
authors.lastname: Jaruwongrungsee
authors.forename: Tanom
authors.initials: T
authors.lastname: Lomas
authors.forename: Adisorn
authors.initials: A
authors.lastname: Tuantranont
mesh_terms: D000318:Adrenergic beta-Agonists / Q000032:analysis*; D000420:Albuterol / Q000032:analysis*; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D017022:Flow Injection Analysis / Q000295:instrumentation* / Q000379:methods; D005898:Glass / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D037742:Nanotubes, Carbon / Q000737:chemistry*; D015203:Reproducibility of Results; D013997:Time Factors; D014835:Volatilization
chemical_list: D000318:Adrenergic beta-Agonists; D004129:Dimethylpolysiloxanes; D037742:Nanotubes, Carbon; C013830:baysilon; D000420:Albuterol