Clinical Medical Research Center, The 2nd Clinic Medicine College (Shenzhen People's Hospital), Jinan University, Shenzhen, PR China.
Clin Chem Lab Med. 2010 Feb;48(2):279-83. doi: 10.1515/CCLM.2010.041.
The sensitivity and selectivity of traditional methods limits ultramicro detection of proteins. Bio-barcode amplification detection methods based on nanotechnology enables ultramicro detection of protein. However, bio-barcode amplification detection depends on the oligonucleotides being fixed on a glass chip. It also requires specialized equipment, which limits its application. We introduce a nano-nucleic acid barcode dot detection technology to determine ultramicro concentrations of protein. The method is simple, quick and accurate.
Magnetic probe (IgG-M) and dual-labeled gold nanoparticle bio-probe (IgG-Au-DNA) were prepared. Protein was captured using a sandwich assay technique and magnetic separation was used. The DNA barcode was released with dithiothreitol (DTT) and detected directly without the requirement for polymerase chain reaction (PCR). Serum prostate-specific antigen (PSA) from 135 patients was detected with this method and compared with enzyme linked immunosorbent assay (ELISA) and radioimmunoassay (RIA).
Each IgG-Au-DNA could be covered with 138+/-47 oligonucleotides and 11+/-3 antibodies. The IgG-M could bind 118 mug of antibody per mg. The sensitivity of nano-nucleic acid barcode dot detection technology might allow detection of 1 fg/mL. There were no significant differences in serum PSA from 135 patients when comparing the three methods (compared with ELISA, r=0.950; and with RIA, r=0.967).
The nucleic acid barcode dot method does not require special equipment or complex procedures, but its detection limit is 2-3 orders of magnitude lower than ELISA.
传统方法的灵敏度和选择性限制了蛋白质的超微量检测。基于纳米技术的生物条码放大检测方法使蛋白质的超微量检测成为可能。然而，生物条码放大检测依赖于固定在玻璃芯片上的寡核苷酸。它还需要专门的设备，这限制了它的应用。我们引入了一种纳米核酸条码点检测技术来测定蛋白质的超微量浓度。该方法简单、快速、准确。
制备磁性探针（IgG-M）和双标记金纳米颗粒生物探针（IgG-Au-DNA）。采用夹心检测技术捕获蛋白质，采用磁分离法。用二硫苏糖醇（DTT）释放 DNA 条码，无需聚合酶链反应（PCR）即可直接检测。用该方法检测了 135 例患者的血清前列腺特异性抗原（PSA），并与酶联免疫吸附试验（ELISA）和放射免疫分析（RIA）进行了比较。
每个 IgG-Au-DNA 可覆盖 138+/-47 个寡核苷酸和 11+/-3 个抗体。IgG-M 可结合每毫克 118 微克抗体。纳米核酸条码点检测技术的灵敏度可检测到 1 fg/mL。三种方法检测的 135 例患者血清 PSA 无显著差异（与 ELISA 相比，r=0.950；与 RIA 相比，r=0.967）。
核酸条码点法不需要特殊设备或复杂的程序，但检测限比 ELISA 低 2-3 个数量级。
