Infrared optical sensor for rapid microbial contamination detection in aqueous solutions

Overview

Max-IR Labs has developed an infrared optical sensing approach that detects microbial contamination in aqueous solutions by analyzing the metabolic activity of microorganisms in real time. Rather than relying on traditional culture-based methods that can take days, the sensor monitors the consumption of energy sources such as carbohydrates and the formation of metabolic end-products (e.g., nitrite, lactate, acetate). This metabolomic profiling enables detection of bacteria such as R. pickettii and B. diminuta at sensitivities below 100 CFU/ml, while also distinguishing between pathogenic and non-pathogenic strains. The technology can additionally detect yeast and differentiate viable from non-viable cells. The company envisions a packaged test format at a target cost of approximately $20 per test, making it suitable for routine water quality monitoring, pharmaceutical manufacturing quality control, clinical diagnostics, and environmental testing.

Technical specifications

How it works:

• The sensor uses fiber-optic infrared spectroscopy to monitor biochemical changes in aqueous samples in real time
• It tracks the disappearance of consumed metabolites (carbohydrates, amino acids, nitrogen sources) and the appearance of metabolic products (acetate, lactate, nitrite, and other nitrogen-cycle intermediates)
• High selectivity allows differentiation between carbohydrate, amino acid, and nitrogen sources, as well as their respective end-products
• Detection focuses on consumed substrates rather than produced metabolites, which the team has found to be a more efficient screening strategy

Key features:

• Real-time monitoring of microbial metabolic activity without lengthy culture steps
• Sensitivity below 100 CFU/ml for target organisms
• Ability to distinguish viable from non-viable cells
• Capability to differentiate between pathogenic and non-pathogenic strains based on metabolomic signatures
• Applicability to bacteria and yeast
• Designed for low-cost packaging at approximately $20 per test

Technology readiness level

The technology has been validated through prior proof-of-concept studies in two application areas. In urinalysis, the team successfully monitored E. coli metabolism in real time, tracking energy source consumption and end-product formation, and differentiating pathogenic from non-pathogenic strains. In environmental microbiology studies with Paracoccus denitrificans, the sensor detected consumption of energy sources such as succinate and glycerol, and tracked intermediates of the nitrogen cycle (nitrate to nitrite to nitric oxide to nitrous oxide to nitrogen gas). Future validation efforts will focus on defining optimal growth conditions for target organisms, selecting the most informative single wavelength for a packaged test, and finalizing a commercial-ready test format. The company is actively seeking a partner to package and commercialize the technology.