Time-resolved single-step protease activity quantification using nanoplasmonic resonator sensors

ACS Nano. 2010 Feb 23;4(2):978-84. doi: 10.1021/nn900757p.


Protease activity measurement has broad application in drug screening, diagnosis and disease staging, and molecular profiling. However, conventional immunopeptidemetric assays (IMPA) exhibit low fluorescence signal-to-noise ratios, preventing reliable measurements at lower concentrations in the clinically important picomolar to nanomolar range. Here, we demonstrated a highly sensitive measurement of protease activity using a nanoplasmonic resonator (NPR). NPRs enhance Raman signals by 6.1 x 10(10) times in a highly reproducible manner, enabling fast detection of proteolytically active prostate-specific antigen (paPSA) activities in real-time, at a sensitivity level of 6 pM (0.2 ng/mL) with a dynamic range of 3 orders of magnitude. Experiments on extracellular fluid (ECF) from the paPSA-positive cells demonstrate specific detection in a complex biofluid background. This method offers a fast, sensitive, accurate, and one-step approach to detect the proteases' activities in very small sample volumes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cell Line, Tumor
  • Enzyme Assays / instrumentation*
  • Enzyme Assays / methods
  • Humans
  • Kinetics
  • Male
  • Nanotechnology*
  • Prostate-Specific Antigen / metabolism*
  • Prostatic Neoplasms / diagnosis
  • Prostatic Neoplasms / enzymology
  • Time Factors


  • Prostate-Specific Antigen