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Analysis of organic environmental pollutants by surface-enhanced laser desorption/ionization mass spectrometry with polydopamine nanospheres as a substrate (CAT#: STEM-ST-0337-LJX)

Introduction

Polydopamine nanospheres (PDA) were designed to serve as a new substrate for surface-enhanced desorption/ionization mass spectrometry (SELDI-MS). Compared with conventional organic matrices, the PDA substrate showed superior LDI performance for analyzing a wide variety of environmental pollutants, including polycyclic aromatic hydrocarbons, bisphenols, benzophenones, sulfonamides, perfluorinated compounds and estrogens. Benzoapyrene was used to evaluate the ability of quantitative analysis and its corresponding limit of detection (LOD) of as low as 0.1 ng was achieved. High sensitivity and good reproducibility of PDA-based SELDI-MS allowed us to determine ultratrace PAHs in airborne particulate matters (PM2.5), and the corresponding concentration of BaP in different PM2.5 were 5.32, 8.97 and 9.79 ng m-3. Significantly, PDA exhibits the characteristics of simple synthesis, low cost, non-toxicity and less matrix interference, which provides the possibility for the sensitive analysis of organic small molecule pollutants at low concentrations in complex environmental samples.




Principle

The surface enhanced laser desorption ionization technique belongs to laser desorption mass spectrometry (LDMS). It is different from ordinary LDMS in that the laser is not directly hit on the sample to desorption, but the sample is suspended in the matrix, the laser is hit on the matrix, the matrix absorbs and transmits the laser energy, so that the sample in the matrix desorption out. After desorption and ionization, the samples were examined in a time-flight mass spectrometer.

Applications

For protein analysis and measurement of molecular weight of complete proteins
For the diagnosis of a variety of diseases, especially cancer

Procedure

1. The surface of the protein chip is treated in a certain chemical or biochemical way (surface enhancement), so that it has the ability to bind specifically to a certain type of protein
2. The serum or protein extract is directly added to the surface of the chip, and the chip is washed after incubation. Specific proteins bind to the chip and are thus separated from the protein mixture
3. The chip then uses a "chip reader" (a kind of SELDI-TOF-MS) to obtain a mass spectrum of the protein bound to the chip
4. The SELDI protein chip system can be used to compare changes in the protein profile of any set of control samples or different disease states to identify biomarkers or disease-related targets

Materials

• Sample Type:
Organic environmental pollutants

Notes

When operating, strictly follow the experimental steps.