Electron transfer mediator micro-biosensor fabrication by organic plasma process

• Published in: Biosensors & bioelectronics 2005-12, Vol.21 (6), p.957-964
• Main Authors: Hiratsuka, Atsunori, Kojima, Ken-ichi, Muguruma, Hitoshi, Lee, Kyong-Hoon, Suzuki, Hiroaki, Karube, Isao
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensors; Biotechnology; Coated Materials, Biocompatible - chemistry; Cross-Linking Reagents - chemistry; Crystallization - methods; Electrochemistry - instrumentation; Electrochemistry - methods; Electron transfer mediator; Electron Transport; Enzyme; Equipment Design; Equipment Failure Analysis; Ferrocene; Ferrous Compounds - chemistry; Fundamental and applied biological sciences. Psychology; Gases - chemistry; Glucose biosensor; Hot Temperature; Methods. Procedures. Technologies; Microelectrodes; Miniaturization; Organic Chemicals - chemistry; Plasma-polymerized film; Various methods and equipments; Vinyl Compounds - chemistry
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2005.03.002

We propose a new strategy for constructing a mediator-type biosensor as a Bio-MicroElectroMechanical Systems (BioMEMS) application. A vinylferrocene plasma-polymerized film (PPF) was deposited directly onto the surface of an electrode under dry conditions. The resulting redox film was extremely thin, adhered well onto a substrate (electrode), and had a highly crosslinked network structure. This technique, capable of polymeric deposition of any kind of monomer, can also serve the purpose of anti-fouling coating, or layer-to-layer interface creation. With a subsequent plasma process, additional polymeric layer of hydrophilic acetonitrile was superimposed onto the existing vinylferrocene-PPF surface to offer crucial features such that the wettability could be adjusted for a better electron transfer, and amino functional groups could be attached to immobilize a large amount of enzyme. Based upon this scheme, the device fabrication could be designed in a manner that the whole procedure was made up of dry wafer-handling processes, which is compatible with mass production. A prototype device was fabricated to have an array of needle-shaped amperometric micro-biosensors. The resultant thin polymer layer carried a large number of the mediator molecules, accomplishing a lower overpotential (+410 mV) and a rapid response time (