Optical detection system for bioaerosol and detection method

Abstract

The invention provides an optical detection system for bioaerosol and a detection method. The detection system comprises a particle counting unit, a gathering unit, a fluorescence detecting unit and a result determining unit. The detection method comprises the following steps: firstly, particle counting is performed on an aerosol sample in the particle counting unit, then particles of the aerosol sample are gathered by the gathering unit, and the gathered aerosol sample is subjected to fluorescence detection by the fluorescence detection unit; the result determining unit receives detection signals of the particle counting unit and the fluorescence detecting unit, and determines whether the detected aerosol sample is bioaerosol. The fluorescence detecting unit adopts a split light path system, and an ultraviolet semiconductor laser is adopted as an ultraviolet light source. The detection system provided by the invention has the advantages of high sensitivity and signal-to-noise ratio, structure flexibility and wide adaptability; the detection method based on the detection system increases the determination basis, has better reliability and reduces the probability of false alarm.

Description

technical field [0001] The invention belongs to the technical field of environmental detection, and in particular relates to a biological aerosol optical detection system, which can monitor the concentration and changes of biological particles such as bacteria and viruses in the ambient atmosphere. The present invention also relates to a bioaerosol detection method using the above optical detection system. Background technique [0002] Microorganisms such as infectious bacteria or viruses exist in the atmosphere in the form of aerosol particles. When the concentration of infectious bacteria or viruses in the atmosphere exceeds a certain threshold, it will pose a threat to the health of humans, animals and plants. The detection of sol particles has become an important part of environmental detection. The organic molecules or molecular groups contained in the microbial particles of bioaerosols, such as amino acids, nicotinamide adenine dinucleotide (NADH), riboflavin and othe...

AI Technical Summary

Problems solved by technology

[0004] Chinese invention patent ZL201010177954.1 discloses a dual-channel real-time bioaerosol monitoring device using multi-aerosol particle fluorescence detection method, which can monitor whether there is bioaerosol in the air through the method of impact enrichment sampling and fluorescence detection, but This technical solution also has the following disadvantages: 1. The ultraviolet light source uses ultraviolet light-emitting diodes. Ultraviolet light-emitting diodes are generally small in size, low in power, and high in price. Their low optical power leads to low detection sensitivity of the instrument.

Ultraviolet light-emitting diodes with higher power are expensive, and the volume is also significantly increased, and the emitted light has a large beam divergence angle, which is not conducive to beam shaping. At the same time, the increase in power will also increase the optical noise and even cause the output signal of the photomultiplier tube Saturation; 2. When the excitation optical path and receiving optical path of the fluorescence detection device are set as a common optical path, as the power of the light source increases, the optical noise of the optical path will also increase, which will affect the detection of fluorescence signals and may reduce the service life of the photomultiplier tube.

Moreover, the fluorescence collection efficiency of the detection optical path system is low, which cannot fully receive the fluorescence emitted by the bioaerosol sample; 3. Although the fluorescence detection uses two wavelengths of excitation light path channels, each channel only detects the total fluorescence intensity of the aerosol sample, so the result judgment is based on less information, which may cause more false alarms in the device

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