We consider the possibilities of applying the plasmon-enhanced fluorescence of monoclonal antibodies labelled with fluorescein isothiocyanate (FITC) to the prostate-specific antigen (PSA) for increasing the immunofluorescence analysis sensitivity. An immunochemical test system featuring two center binding using a pair of noncompeting monoclonal antibodies in combination with silver plasmon nanoparticles was used for the first time for determining the PSA concentration. The advantages over the standard PSA immunofluorescence assay are as follows. The intensity of the recorded fluorescent signal is enhanced by 2.3–3.2 times in the presence of silver nanoparticles in comparison with the signal of the test system on the intact surface of a polystyrene plate. The signal-to-noise ratio is increased by up to two times. In addition to the plasmon-enhanced fluorescence, the effect of an intermediate polyelectrolyte layer for enhancement of the adsorption capacity of the primary PSA antibodies is shown, which, in turn, affects the fluorescence signal intensity. Growth of the plasmon fluorescence enhancement factor with increasing concentration of the labelled antibodies indicates suppression of the self-quenching of the fluorescent labels by metal nanoparticles.

我们考虑将标记有异硫氰酸荧光素（FITC）的单克隆抗体的等离子体增强荧光应用于前列腺特异性抗原（PSA）的可能性，以提高免疫荧光分析的灵敏度。首次使用具有一对非竞争性单克隆抗体和银等离激元纳米粒子的结合的两个中心结合的免疫化学测试系统来确定PSA浓度。相对于标准PSA免疫荧光测定法的优势如下。与在聚苯乙烯板完整表面上的测试系统的信号相比，在存在银纳米颗粒的情况下，记录的荧光信号的强度提高了2.3-3.2倍。信噪比最多增加两倍。除了等离激元增强的荧光之外，还显示了中间聚电解质层对一级PSA抗体吸附能力的增强作用，进而影响了荧光信号强度。随着标记抗体浓度的增加，等离激元荧光增强因子的生长表明金属纳米颗粒抑制了荧光标记的自猝灭。