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

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 LCMS/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