Open AccessNoninvasive biosensor for cathepsin L in the stratum corneum
Author(s) -
Yamaguchi Masaki,
Date Akira,
Sasaki Makoto,
Makino Teruhiko,
Shimizu Tadamichi
Publication year - 2012
Publication title -
skin research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.521
H-Index - 69
eISSN - 1600-0846
pISSN - 0909-752X
DOI - 10.1111/j.1600-0846.2011.00565.x
Subject(s) - stratum corneum , biosensor , chromatography , biomedical engineering , materials science , chemistry , nanotechnology , pathology , medicine
Purpose The objective is to propose an on‐site testing biosensor of cathepsin L ( CatL ) activity in the stratum corneum, which can be used for the evaluation of skin conditions noninvasively and easily. Methods The biosensor comprises of a disposable test strip and a desktop‐sized reader (260 × 150 × 290 mm 3 , 1.9 kg), incorporating a charge‐coupled device image sensor ( CCD ) unit to measure the reflectance of the test strip. A novel immuno‐chromatographic test strip was proposed for CatL analysis in the stratum corneum. In order to realize the test strip, a colloidal gold technique was selected as the molecular recognition method for the CatL . A human skin sample was collected noninvasively by adhesive tape stripping. Results Based on optimal assay conditions, the sensitivity of the biosensor was evaluated. It required 10 min from a sample dropping to appear the test line on the test strip. The optical density was proportion to the CatL . Bioanalytical validation indicated that, within the biosensor's detection limit (172.2 μU/mL), its accuracy ( R 2 = 0.94), and precision ( CV = 15%) approach more elaborate laboratory‐based analyzers. In addition, the truncated sampling‐reporting cycle (<15 min) allows speedy reporting of CatL levels. Conclusion It was indicated that this noninvasive and easy‐to use biosensor might be a novel tool for the semi‐quantitative analysis of CatL in the stratum corneum.