Fluorescence-optical handheld non-contact sensor for rapid cleaning validation of surfaces

Abstract Background and objective: Thin films of bacteria, proteins and other biochemical substances are always found on surfaces exposed to the environment. Optical methods enable innovative tools for the detection of such films, as residua of proteins and other substances that exhibit fluorescence when excited with UV light. Sensor design: This paper presents and evaluates a specially designed handheld measuring device for this purpose. Results: The sensor is able to detect low concentrations of organic contamination with measurement times shorter than a second. The results presented in this paper show that detection of contamination levels of bovine serum albumin down to 200 ng/cm2 is possible on non-fluorescent substrate materials. Conclusion: Future development of handheld optical devices suitable for the detection or analysis of various compounds could be based on these results.