Preparation and Immunoassay Application of Polyethylene Glycol Grafted Styrene Maleic Acid Copolymer Composite Microspheres

doi:10.16183/j.cnki.jsjtu.2020.029

Abstract

Abstract:

In the quantum dot-encoded microspheres based on the suspension array technology, the nonspecific biofouling will decrease the detection sensitivity and the multiplex detection ability. In order to inhibit the nonspecific biofouling, the polyethylene glycol grafted styrene maleic acid copolymer (PEG-g-PSMA) was used as substrate, and the CuInS₂/ZnS quantum dot-encoded PEG-g-PSMA fluorescent microspheres were fabricated via the Shirasu porous glass (SPG) membrane emulsification-emulsion solvent evaporation technique. The grafting ratio and the chain length of PEG in PEG-g-PSMA were controlled by adjusting the feed mass and relative molecular mass of methoxy polyethylene glycol (mPEG), respectively. The microspheres were further applied to the immunoassay of CA199. The results of morphology and fluorescence properties show that the prepared microspheres are spherical and monodisperse, with an average particle size of 5 μm, and the internal quantum dots and fluorescence distribution are uniform. Immunoassay shows that the microspheres can significantly inhibit the nonspecific adsorption. When the optimal grafting ratio of PEG is 30 and the relative molecular mass of PEG is 1000, the limit of detection (LOD) to CA199 reaches up to 0.9 kU/L (1 U=1 μmol/min). The PEG-g-PSMA fluorescent microspheres can be prepared in large quantites by this method and have a promising application in multiplex immunoassay.

Key words: polymeric microsphere, suspension array, polyethylene glycol (PEG), nonspecific biofouling suppression

CLC Number:

O647.3
TQ317

ZHANG Xiannan, LENG Yuankui, WU Weijie, LI Wanwan. Preparation and Immunoassay Application of Polyethylene Glycol Grafted Styrene Maleic Acid Copolymer Composite Microspheres[J]. Journal of Shanghai Jiao Tong University, 2021, 55(9): 1064-1070.

Figures/Tables 10

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缓冲液	组分	组分质量/g	溶剂体积/mL	pH
PBS	Na₂HPO₄·12H₂O	7.26	2000	7.4
	KH₂PO₄	0.48
	NaCl	16.146
	KCl	0.403
活化液	NaH₂PO₄	0.6	50	6.2
	NaOH	0.08
洗涤液	吐温-20	0.11	200	7.4
1^#储存液	BSA	0.2	200	7.4
	吐温-20	0.044
	硫柳汞钠	0.04
2^#储存液	吐温-20	0.044	200	7.4
	硫柳汞钠	0.04
1^#分析液	BSA	2	200	7.4
	硫柳汞钠	0.04
2^#分析液	甘氨酸	2	200	7.4
	硫柳汞钠	0.04

接枝聚合物	m(mPEG)/m(PSMA)	N
15PEG1000-g-PSMA	0.5	17
30PEG1000-g-PSMA	1	31
50PEG1000-g-PSMA	2	50
100PEG1000-g-PSMA	4	100
30PEG550-g-PSMA	0.33	32
30PEG2000-g-PSMA	1	29
30PEG5000-g-PSMA	1	30

微球	无BSA的检测限	含BSA的检测限
PSMA	5.3	2.0
15PEG1000-g-PSMA	2.7	1.3
30PEG1000-g-PSMA	0.9	0.8
50PEG1000-g-PSMA	1.0	1.1
100PEG1000-g-PSMA	1.3	1.3
30PEG550-g-PSMA	4.3	1.4
30PEG2000-g-PSMA	1.6	1.5
30PEG5000-g-PSMA	1.9	1.9