Monitoring extracellular K+ flux with a valinomycin-coated silicon nanowire field-effect transistor.
A silicon nanowire field-effect transistor (SiNW-FET) coated with a polyvinyl chloride (PVC) membrane containing valinomycin (VAL) was employed as a biosensor (referred to as VAL-PVC/SiNW-FET) to detect the K(+)-efflux from live chromaffin cells. The detection sensitivity of K(+) with the VAL-PVC/SiNW-FET covers a broad range of concentrations from 10(-6) to 10(-2) M. The apparent association constants between VAL and Li(+), Na(+), K(+), and Cs(+) in Tris buffer solution were determined to be 67±42, 120±23, 5974±115, and 4121±140 M(-1), respectively. By culturing chromaffin cells on the VAL-PVC/SiNW-FET, the conductance was significantly increased by nicotine stimulation in a bath buffer without Na(+). The K(+) concentration at the cell surface was determined to be ~20 μM under the stimulation of 5 mM nicotine. These results demonstrate that the VAL-PVC/SiNW-FET is sensitive and selective to detect the released K(+) from cells and is suitable for applications in cellular recording investigations.
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
Ko-Shing
KS
Chang
Chih-Jung
CJ
Sun
Pei-Ling
PL
Chiang
Ai-Chuan
AC
Chou
Ming-Chou
MC
Lin
Chieh
C
Liang
Hui-Hsing
HH
Hung
Yu-Hsiu
YH
Yeh
Chii-Dong
CD
Chen
Chien-Yuan
CY
Pan
Yit-Tsong
YT
Chen
D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D002417:Cattle; D002478:Cells, Cultured; D019439:Chromaffin Cells / Q000187:drug effects / Q000378:metabolism*; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003217:Conductometry / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005434:Flow Cytometry / Q000295:instrumentation*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D049329:Nanostructures / Q000737:chemistry; D009538:Nicotine / Q000494:pharmacology; D011188:Potassium / Q000737:chemistry / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry; D014173:Transistors, Electronic; D014634:Valinomycin / Q000737:chemistry*
D020099:Coated Materials, Biocompatible; D014634:Valinomycin; D009538:Nicotine; D011188:Potassium; D012825:Silicon