CCD camera turns into a remote detection and identification of pathogens device
CCD camera turns into a remote detection and identification of pathogens device lead image
Beyond collecting bacteria for future laboratory analysis, it is difficult to detect pathogens in the field in real time, because the necessary instrumentation is prohibitively large and requires a great deal of power. Dhankhar et al. demonstrated a method of using a commercially available charge-coupled device (CCD) camera as a hand-held spectrometer to record and identify the ratio of live to dead bacteria and their strains from meters away.
In a matter of minutes, the authors’ device can obtain the fluorescence and Raman spectra of most molecules, pathogens and viruses in situ. Because concentrations of the amino acids tryptophan and tyrosine vary with bacterial strain, the instrument monitors changes in the fluorescence intensity of these amino acids. It uses both spectral and fluorescence analyses to differentiate between strains and determine the response to treatment.
“Our device enables one to detect and identify bacteria from a distance in water, emergency rooms, wounds in the field and surgical operations within minutes without touching them,” said author Peter Rentzepis.
Most modern CCD cameras include a number of cutoff filters and masks to disable the transmission of ultraviolet light, but the fluorescence of biomolecules, like tryptophan, falls within this range. By simply removing these unwanted components from a monochrome camera and attaching a grating spectrometer to it, the camera becomes an instrument for remote bacterial detection.
This system can be modified for use at even larger distances, enabling the straightforward recording of viruses, plants and other pathogens. Used in many cellphones, the necessary CCD cameras are ubiquitous and easily accessible.
Source: “A novel approach for remote detection of bacteria using simple charge-coupled device cameras and telescope,” by Dinesh Dhankhar, Runze Li, Anushka Nagpal, Jie Chen, Arjun Krishnamoorthi, and Peter M. Rentzepis, Review of Scientific Instruments (2020). The article can be accessed at https://doi.org/10.1063/5.0010701 .
