Analyzing refractive index changes and differential bending in microcantilever arrays.
A new microcantilever array design is investigated comprising eight flexible microcantilevers introducing two solid bars, enabling to subtract contributions from differences in refractive index in an optical laser read out system. Changes in the refractive index do not contribute undesirably to bending signals at picomolar to micromolar DNA or protein concentrations. However, measurements of samples with high salt concentrations or serum are affected, requiring corrections for refractive index artifacts. Moreover, to obtain a deeper understanding of molecular stress formation, the differential curvature of cantilevers is analyzed by positioning the laser spots along the surface of the levers during pH experiments.
Huber
François
F
NCCR Nanoscale Science, Institute of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland. francois.huber@unibas.ch
Lang
Hans Peter
HP
Hegner
Martin
M
Despont
Michel
M
Drechsler
Ute
U
Gerber
Christoph
C
D000818:Animals; D016477:Artifacts; D002021:Buffers; D002417:Cattle; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007834:Lasers; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D019308:Palmitic Acid / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D012015:Reference Standards; D012031:Refractometry / Q000295:instrumentation*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014025:Titanium / Q000737:chemistry
D002021:Buffers; D010710:Phosphates; D013438:Sulfhydryl Compounds; D012710:Serum Albumin, Bovine; C086974:hexadecanethiol; D019308:Palmitic Acid; D012965:Sodium Chloride; D006046:Gold; D014025:Titanium