Fast cholesterol detection using flow injection microfluidic device with functionalized carbon nanotubes based electrochemical sensor.
This work reports a new cholesterol detection scheme using functionalized carbon nanotube (CNT) electrode in a polydimethylsiloxane/glass based flow injection microfluidic chip. CNTs working, silver reference and platinum counter electrode layers were fabricated on the chip by sputtering and low temperature chemical vapor deposition methods. Cholesterol oxidase prepared in polyvinyl alcohol solution was immobilized on CNTs by in-channel flow technique. Cholesterol analysis based on flow injection chronoamperometric measurement was performed in 150-μm-wide and 150-μm-deep microchannels. Fast and sensitive real-time detection was achieved with high throughput of more than 60 samples per hour and small sample volume of 15 μl. The cholesterol sensor had a linear detection range between 50 and 400 mg/dl. In addition, low cross-sensitivities toward glucose, ascorbic acid, acetaminophen and uric acid were confirmed. The proposed system is promising for clinical diagnostics of cholesterol with high speed real-time detection capability, very low sample consumption, high sensitivity, low interference and good stability.
Wisitsoraat
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A
Nanoelectronics and MEMS Laboratory, National Electronics and Computer Technology Center, 112 Pahol Yothin Rd., Pathumthani 12120, Thailand. anurat.wisitsoraat@nectec.or.th
Sritongkham
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P
Karuwan
C
C
Phokharatkul
D
D
Maturos
T
T
Tuantranont
A
A
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000706:statistics & numerical data; D001774:Blood Chemical Analysis / Q000295:instrumentation; D002784:Cholesterol / Q000032:analysis* / Q000097:blood; D002789:Cholesterol Oxidase; D055664:Electrochemical Techniques; D004800:Enzymes, Immobilized; D004867:Equipment Design; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000706:statistics & numerical data; D008855:Microscopy, Electron, Scanning; D037742:Nanotubes, Carbon / Q000648:ultrastructure; D017550:Spectroscopy, Fourier Transform Infrared
D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D002784:Cholesterol; D002789:Cholesterol Oxidase