Institute of Comparative Medicine, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China , Yangzhou University , Yangzhou 225009 , China.
Future Industries Institute and ARC Centre of Excellence in Convergent Bio and Nano Science and Technology, Mawson Lakes Campus , University of South Australia , South Australia 5095 , Australia.
ACS Appl Mater Interfaces. 2019 Feb 20;11(7):6769-6776. doi: 10.1021/acsami.8b19055. Epub 2019 Feb 6.
Currently, it remains challenging to count protein-biomarker molecules present in a small droplet of biological samples. Herein, we propose a gold nanoparticle (GNP) probe-assisted sandwich-counting strategy that relies on a GNP probe, an antibody-functionalized chip to "count" antigen molecules using a scanning electron microscope. Both standard carcinoembryonic antigen (CEA) and two real CEA-related tumor samples (tumor tissues and serum) were assayed to demonstrate the proof-of-concept of the counting strategy. Results show that our method is excellently correlative with enzyme-linked immuno-sorbent assay (ELISA) that is widely used in clinics for antigen or antibody detection and the limit of detection of our enumeration strategy reaches down to 0.045 ng/mL, which is ∼40 times more sensitive than the conventional ELISA. Therefore, our GNP probe-assisted sandwich-counting strategy has the potential to be used for quantification of protein biomarkers at ultralow concentrations in early tumor specimens and detection of target proteins in much diluted concentrations.
目前，在小体积的生物样本液滴中对蛋白质生物标志物分子进行计数仍然具有挑战性。在此，我们提出了一种金纳米颗粒（GNP）探针辅助的三明治计数策略，该策略依赖于 GNP 探针和抗体功能化芯片，使用扫描电子显微镜“计数”抗原分子。使用该计数策略对标准癌胚抗原（CEA）和两个实际的 CEA 相关肿瘤样本（肿瘤组织和血清）进行了检测，以证明其概念验证。结果表明，我们的方法与临床上广泛用于抗原或抗体检测的酶联免疫吸附测定（ELISA）具有极好的相关性，我们的计数策略的检测限低至 0.045ng/mL，比传统 ELISA 灵敏约 40 倍。因此，我们的 GNP 探针辅助三明治计数策略有可能用于在早期肿瘤标本中对超低浓度的蛋白质生物标志物进行定量，并检测在大大稀释浓度下的靶蛋白。
