title: Investigation on light-addressable potentiometric sensor as a possible cell-semiconductor hybrid.
abstract: This article reports an investigation on light-addressable potentiometric sensor (LAPS) to be used as a possible biological cell-semiconductor hybrid that will enable us to make an interface between the physical and biological system. To increase the surface potential sensitivity, we used a LAPS structure with single insulator (SiO2) coated with poly-L-ornithine and laminin (PLOL) on Si. Efficient culturing of PC-12 and nerve cells of Lymnaea stagnalis on PLOL-coated Si3N4 and SiO2 was achieved. The thickness of the PLOL layer was found to be about 4 nm by the atomic force microscope (AFM) measurement. Using the advantage of this thin layer of PLOL, we compared the performance of a novel structure to the previously reported "PLOL-coated Si3N4/SiO2/Si" structure. Due to high insulating capacitance, the photocurrent response of the novel LAPS was found to be very steep. As a result, higher sensitivity was achieved. This steepness did not degrade during 10 days when the sensor surface was kept in contact with the cell culture medium and environment. The thickness of PLOL layer, its ability to improve the biological cell adhesion, enhanced sensitivity, and experiment with simulated neural action potential (AP) applied to the novel LAPS show a good promise for LAPS to be a biological cell-semiconductor hybrid.
authors.affiliation: Department of Applied Physics and Electronics, Rajshahi University, Rajshahi 6205, Bangladesh. ismail@librabd.net
authors.forename: Abu Bakar Md
authors.initials: AB
authors.lastname: Ismail
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yoshinobu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iwasaki
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Sugihara
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Yukimasa
authors.forename: Isao
authors.initials: I
authors.lastname: Hirata
authors.forename: Hiroo
authors.initials: H
authors.lastname: Iwata
mesh_terms: D000200:Action Potentials / Q000502:physiology* / Q000528:radiation effects*; D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002448:Cell Adhesion / Q000502:physiology / Q000528:radiation effects; D018929:Cell Culture Techniques / Q000295:instrumentation / Q000379:methods; D002478:Cells, Cultured; D004307:Dose-Response Relationship, Radiation; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D008027:Light; D008195:Lymnaea / Q000502:physiology / Q000528:radiation effects; D009474:Neurons / Q000502:physiology* / Q000528:radiation effects*; D010783:Photometry / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012666:Semiconductors; D012680:Sensitivity and Specificity