Method for detecting microalgae content in ship ballast water

Abstract

The invention belongs to the technical field of ship ballast water microalgae content detection, and particularly relates to an up-conversion nano fluorescent probe which realizes rapid detection of microalgae content through competitive emission. According to the method, a red up-conversion nano fluorescent probe is adopted, red luminescence of the fluorescent probe is highly overlapped with the maximum absorption peak of ballast water microalgae chlorophyll a under excitation of near-infrared light, a relation curve of luminescence intensity and the content of chlorophyll a is established through competitive luminescence measurement, and the content of the chlorophyll a is determined according to the corresponding relation of the content of the chlorophyll a and the microalgae cell biomass. And establishing a relation model between the luminous intensity and the microalgae cell biomass so as to calculate the microalgae biomass in the ballast water sample. According to the present invention, the rapid detection of the microalgae biomass can be achieved, the operation is simple and convenient, the sensitivity is high, the safe long wavelength near-infrared light is adopted as the excitation source, the light damage to the organism is reduced, the spontaneous background fluorescence of the microalgae cannot be caused, the detection sensitivity can be improved in the order of magnitude, and the method is suitable for promotion and application.

Description

technical field [0001] The invention relates to the technical field of detection of microalgae content in ship's ballast water, in particular to the rapid detection of microalgae content by using up-conversion fluorescent probes and competitive emission. Background technique [0002] With the increasingly globalized economic development, shipping currently undertakes more than 80% of global cargo transportation. In order to control the ship's heel, trim, draft, stability or stress, and ensure the stability and maneuverability of the ship during navigation, it is necessary to load ballast water on the ship. However, the ship’s ballast water carries a large number of aquatic organisms, such as phytoplankton, zooplankton, bacteria, viruses, etc. These alien aquatic organisms will invade the local marine ecosystem with the absorption and discharge of ballast water, causing alien organisms to invade, Red tides and other serious disasters, therefore, are listed as one of the four...

AI Technical Summary

Problems solved by technology

However, there is still a lack of rapid detection methods for microalgal cells in ship's ballast water

[0003] At present, the main detection methods: 1) microscopic counting method, by observing the microalgae cells under a microscope, distinguishing and counting by the size, shape and color of the cells, inferring, but this method requires professionals to detect, manual counting errors 2) Flow cytometry method, using flow cytometry to measure the suspension containing microalgae passing through the laser irradiation area, and measuring the light intensity of the microalgae cells labeled with the dye Signal, to determine the content of microalgae, this method has the advantages of accuracy and high efficiency, but commercial flow cytometers are expensive, bulky, and sample pretreatment is cumbersome, and it is difficult to achieve rapid detection of ballast water tanks; 3) Chlorophyll fluorescence Because chlorophyll a widely exists in all algae, the concentration of chlorophyll a has become the most commonly used indicator to measure the biomass of microalgae

The methods for measuring chlorophyll a concentration mainly include fluorescence spectrophotometry (direct fluorescence spectrophotometry for rapid determination of chlorophyll a in water, Journal of Wuhan University of Technology, 2011, 33, 112-115) and absorption spectrophotometry (a fast and accurate microscopic Algae biomass estimation method, Acta Physiology of Plants, 2021, 57, 216-224): Fluorescence spectrophotometry uses the characteristic of chlorophyll a in marine microalgae to emit red light (680nm) under the excitation of blue light (420nm), and establishes the characteristics of chlorophyll a The correlation between the content and the luminous intensity is used to calibrate the algae biomass, but this method has low sensitivity. Due to the weak fluorescence of chlorophyll, it is not suitable for the content test of low-concentration chlorophyll a; Absorption spectrophotometry uses algae chlorophyll a There are absorption characteristics at ≈649 and ≈665nm wavelengths, and the chlorophyll a content of the sample is calculated by the absorbance value. Further, the patent CN 111896482 A reports the establishment of a model of the color parameters and chlorophyll content of the Chlorella sample, so as to calculate the chlorophyll a content

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