Label-free Porous Silicon Immunosensor for Broad Detection of Opiates in a Blind Clinical Study and Results Comparison to Commercial Analytical Chemistry Techniques

Anal Chem. 2010 Dec 1;82(23):9711-8. doi: 10.1021/ac101804s. Epub 2010 Nov 9.


In this work, we evaluate for the first time the performance of a label-free porous silicon (PSi) immunosensor assay in a blind clinical study designed to screen authentic patient urine specimens for a broad range of opiates. The PSi opiate immunosensor achieved 96% concordance with liquid chromatography-mass spectrometry/tandem mass spectrometry (LC-MS/MS) results on samples that underwent standard opiate testing (n = 50). In addition, successful detection of a commonly abused opiate, oxycodone, resulted in 100% qualitative agreement between the PSi opiate sensor and LC-MS/MS. In contrast, a commercial broad opiate immunoassay technique (CEDIA) achieved 65% qualitative concordance with LC-MS/MS. Evaluation of important performance attributes including precision, accuracy, and recovery was completed on blank urine specimens spiked with test analytes. Variability of morphine detection as a model opiate target was <9% both within-run and between-day at and above the cutoff limit of 300 ng mL(-1). This study validates the analytical screening capability of label-free PSi opiate immunosensors in authentic patient samples and is the first semiquantitative demonstration of the technology's successful clinical use. These results motivate future development of label-free PSi technology to reduce complexity and cost of diagnostic testing particularly in a point-of-care setting.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Analgesics, Opioid / urine*
  • Biosensing Techniques / methods*
  • Chromatography, High Pressure Liquid
  • Gas Chromatography-Mass Spectrometry
  • Humans
  • Immunoassay / methods*
  • Mass Spectrometry
  • Morphine / urine
  • Oxycodone / urine*
  • Point-of-Care Systems
  • Porosity
  • Silicon / chemistry*


  • Analgesics, Opioid
  • Morphine
  • Oxycodone
  • Silicon