Spectroscopy and Spectral Analysis, Volume. 43, Issue 9, 2805(2023)

Screening of DNA Dyes for Colorimetric Sensing Via Rapidly Inducing Gold Nanoparticles Aggregation

YE Zi-yi, LIU Shuang, and ZHANG Xin-feng
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  • [in Chinese]
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    In recent years, gold nanoparticles (AuNPs) have been widely used in developing and utilising colorimetric sensors due to their extremely high extinction coefficient and distance-dependent color. Common salt-induced AuNP aggregation is carried out using charge shielding, the aggregation process is easily disturbed, and the color is often unstable after aggregation. DNA dyes achieve AuNPs aggregation by charge neutralization, which has the advantages of less dosage and faster aggregation speed. Fast and stable. Therefore, it is necessary to screen for common DNA dyes. In this paper, eight common DNA dyes, including EB, AO, TO, SG, PG, TOTO-1, TOTO-3 and YOYO, were systematically screened for inducing the rapid aggregation of AuNPs. Experiments found that the amount of dye to induce AuNPs agglomeration was between 0.18 and 2.6 μmol·L-1, about 10 000 times lower than the traditional method of inducing aggregation with NaCl and Cys dosages of 60 mmol·L-1 and 20 mmol·L-1, respectively. In addition, the aggregation efficiency was evaluated by examining the “IC50” value of DNA dye-induced AuNPs aggregation (that is, the concentration of 50% of the maximum absorbance change (A680/A520) of AuNPs aggregation induced by the inducer). Among the eight DNA dyes screened, SG The “IC50” values of, PG, TOTO-1, TOTO-3 and YOYO molecules were between 0.12 and 0.30 μmol·L-1, which were relatively small, and the aggregation efficiency of AuNPs was high. Since the number of positively charged N atoms plays a key role in the aggregation of AuNPs, the more positively charged N atoms, the less the amount of neutralizing AuNPs. The number of positively charged N atoms was calculated through the microspecies and microspecies distribution in Marvin View. The results show that pH=7, SG, PG, TOTO-1, TOTO-3, And YOYO molecules have more positively charged N atoms, so the above dye-induced AuNPs aggregation efficiency is high. At the same time, the binding ratio of double-stranded DNA (dsDNA) base pairs to DNA dyes was calculated by the Job curve. The results showed that the binding ratios of the 8 kinds of DNA dyes screened to dsDNA base pairs were similar under the same conditions. Based on the binding ratio, the binding constants of dsDNA and DNA dyes were calculated by combining the experimental fitting curves. The calculation showed that the binding constants of SG, YOYO, TOTO-3, PG and dsDNA were relatively large, ranging from 2.75×109 to 3.12×1010 L·mol-1, and the binding ability to DNA is stronger. Taken together, SG, PG, YOYO, TOTO-3 and other dyes are effective in rapidly inducing AuNPs aggregation and colorimetric sensing.

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    YE Zi-yi, LIU Shuang, ZHANG Xin-feng. Screening of DNA Dyes for Colorimetric Sensing Via Rapidly Inducing Gold Nanoparticles Aggregation[J]. Spectroscopy and Spectral Analysis, 2023, 43(9): 2805

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    Paper Information

    Received: May. 17, 2022

    Accepted: --

    Published Online: Jan. 12, 2024

    The Author Email:

    DOI:10.3964/j.issn.1000-0593(2023)09-2805-06

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