Abstract
Accurate detection and quantification of biomarkers at ultra-low levels is critical for disease diagnosis and effective treatment. Traditional detection technologies often lack the sensitivity, specificity, throughput, or multiplexing capacity required for comprehensive diagnostics, providing only a subset of these requirements. Here, we introduce AVAC, an automated optical technology for rapid and accurate biomarker detection with ultra-high sensitivity that significantly outperforms standard clinical assays. The core of this technology is the digital counting of plasmonic nanoparticles used as optical labels, enabling multiplexed, high-throughput detection of biomarkers. Validation studies demonstrate AVAC's high accuracy, with 98.2% specificity and detection limits as low as 26 fg/mL for HIV p24 protein and a quantification range of 160 fg/mL to 850 pg/mL for interleukin-6 (IL-6). The technology supports multiplexed assays without compromising sensitivity, as demonstrated by the simultaneous detection of three key biomarkers associated with cardiovascular disease. A counting range spanning more than four orders of magnitude ensures robust detection from ultra-low to high biomarker concentrations, and its ability to analyze up to 1,000 samples per hour provides high throughput suitable for large laboratories. With its unique combination of capabilities, this versatile platform has significant potential to advance biomarker-based diagnostics in clinical and research settings.