title: Fabrication of a microneedle/CNT hierarchical micro/nano surface electrochemical sensor and its in-vitro glucose sensing characterization.
abstract: We report fabrication of a microneedle-based three-electrode integrated electrochemical sensor and in-vitro characterization of this sensor for glucose sensing applications. A piece of silicon was sequentially dry and wet etched to form a 15 × 15 array of tall (approximately 380 µm) sharp silicon microneedles. Iron catalyst was deposited through a SU-8 shadow mask to form the working electrode and counter electrode. A multi-walled carbon nanotube forest was grown directly on the silicon microneedle array and platinum nano-particles were electrodeposited. Silver was deposited on the Si microneedle array through another shadow mask and chlorinated to form a Ag/AgCl reference electrode. The 3-electrode electrochemical sensor was tested for various glucose concentrations in the range of 3~20 mM in 0.01 M phosphate buffered saline (PBS) solution. The sensor's amperometric response to the glucose concentration is linear and its sensitivity was found to be 17.73 ± 3 μA/mM-cm2. This microneedle-based sensor has a potential to be used for painless diabetes testing applications.
authors.affiliation: Department of Electrical Engineering, the University of Texas at Dallas, 800 W. Campbell Rd., Richardson, TX 75080, USA. jbleeutd@gmail.com.
authors.forename: Youngsam
authors.initials: Y
authors.lastname: Yoon
authors.forename: Gil S
authors.initials: GS
authors.lastname: Lee
authors.forename: Koangki
authors.initials: K
authors.lastname: Yoo
authors.forename: Jeong-Bong
authors.initials: JB
authors.lastname: Lee
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D004566:Electrodes; D005947:Glucose / Q000737:chemistry*; D037742:Nanotubes, Carbon; D009339:Needles; D010984:Platinum / Q000737:chemistry; D012825:Silicon / Q000737:chemistry; D012834:Silver / Q000737:chemistry
chemical_list: D037742:Nanotubes, Carbon; D012834:Silver; D010984:Platinum; D005947:Glucose; D012825:Silicon