The label-free optical biosensor for an automated, ultra-sensitive and highly accurate microorganisms identification

Abstract The microorganisms identification can be achieved by light diffraction phenomenon leading to the generation of unique optical signatures. This paper is focused on an alternative configuration of the integrated optical biosensor at fixed incubation time, which makes possible the integration of the proposed system into automated specimen processing workflow common for microbiological laboratories. Influence of the intensity distribution of the illuminating beam and iris diaphragm diameter on the deformation of diffraction is indicated. The crucial influence of the registration distance on classification accuracy is indicated as an essential factor limiting the identification, what was confirmed by analysis of over 48 400 patterns. The complex examination of the accuracy of the proposed technique is performed based on highly representative data containing over 100 000 patterns of 12 species including 88 strains. The proposed method enables the identification with accuracy between 97-100%.