Single-cell HER2 quantification via instant signal amplification in microdroplets

Liu，Xiaoxian1,2; Zhu，Yifan1,2; Li，Caoxin1,2; Fang，Yanyun3; Chen，Jinna4; Xu，Fei1; Lu，Yanqing1; Shum，Perry Ping4; Liu，Ying3; Wang，Guanghui1,2

2023-04-22

10.1016/j.aca.2023.340976

ANALYTICA CHIMICA ACTA   Impact Factor & Quartile

0003-2670

1873-4324

Accurate and ultrasensitive evaluation of human epidermal growth factor receptor 2 (HER2) protein is key to early diagnosis and subtype differentiation of breast cancer. Single-cell analyses to reduce ineffective targeted therapies due to breast cancer heterogeneity and improve patient survival remain challenging. Herein, we reported a novel droplet microfluidic combined with an instant cation exchange signal amplification strategy for quantitative analysis of HER2 protein expression on single cells. In the 160 μm droplets produced by a tapered capillary bundle, abundant Immuno-CdS labeled on HER2-positive cells were replaced by Ag to obtain Cd that stimulated Rhod-5N fluorescence. This uniformly distributed and instantaneous fluorescence amplification strategy in droplets improves sensitivity and reduces signal fluctuation. Using HER2 modified PS microsphere to simulate single cells, we obtained a linear fitting of HER2-modified concentration and fluorescence intensity in microdroplets with the limit detection of 11.372 pg mL. Moreover, the relative standard deviation (RSD) was 4.2-fold lower than the traditional immunofluorescence technique (2.89% vs 12.21%). The HER2 protein on SK-BR-3 cells encapsulated in droplets was subsequently quantified, ranging from 9862.954 pg mL and 205.26 pg mL, equivalent to 9.795 × 10 and 2.038 × 10 protein molecules. This detection system provides a universal platform for single-cell sensitive quantitative analysis and contributes to the evaluation of HER2-positive tumors.

Droplet microfluidics HER2 protein expression Instant cation exchange signal amplification Quantitative detection Single-cell

SCI

English

Others

National Natural Science Founda-tion of China["61875083","61535005"] ; Social Development Project of Jiangsu Province[BE2019761]

Chemistry

Chemistry, Analytical

WOS:000949470200001

ELSEVIER

CHEMISTRY

2-s2.0-85148683484

Scopus

1.College of Engineering and Applied Sciences,Nanjing University,Jiangsu,210093,China
2.Key Laboratory of Intelligent Optical Sensing and Integration of the Ministry of Education,Nanjing University,Jiangsu,210009,China
3.School of Chemistry and Chemical Engineering,Nanjing University,Jiangsu,210093,China
4.Department of Electrical and Electronics Engineer,Southern University of Science and Technology,Shenzhen,518055,China

Liu，Xiaoxian,Zhu，Yifan,Li，Caoxin,et al. Single-cell HER2 quantification via instant signal amplification in microdroplets[J]. ANALYTICA CHIMICA ACTA,2023,1251.

Liu，Xiaoxian.,Zhu，Yifan.,Li，Caoxin.,Fang，Yanyun.,Chen，Jinna.,...&Wang，Guanghui.(2023).Single-cell HER2 quantification via instant signal amplification in microdroplets.ANALYTICA CHIMICA ACTA,1251.

Liu，Xiaoxian,et al."Single-cell HER2 quantification via instant signal amplification in microdroplets".ANALYTICA CHIMICA ACTA 1251(2023).