Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, China.
Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering, College of Mechatronics and Control Engineering, Shenzhen University, Shenzhen, 518060, China.
Anal Chim Acta. 2019 Nov 4;1079:200-206. doi: 10.1016/j.aca.2019.06.060. Epub 2019 Jun 29.
Arginine is an important amino acid in humankind bodies and is of essential clinical significance. This paper presents a novel bioprobe based on fluorescence resonance energy transfer (FRET), which can be used to detect arginine efficiently and economically. In this bioprobe system, positively charged up-conversion phosphor NaYF (NYF) acts as energy donor, and negatively charged gold nanoparticle (AuNP) acts as energy acceptor. The oppositely charged donor and acceptor come into close proximity through electrostatic attraction effect, which results in the occurrence of FRET between NYF and AuNP. The FRET process is thus in the "on" state, meanwhile the system is in the "off" state, and the emitting light of NYF quenched. When positively charged arginine is added into the system, the guanidyl of arginine binds to AuNP and leads to the negatively charged AuNP becomes positively charged one, and the AuNP separates from NYF because of the electrostatic repulsion. The FRET process is blocked and the system switches to the "on" state because the distance between NYF and AuNP becomes longer. In the "on" state, the intensity of the restored emitting light is proportional to the concentration of arginine. This approach brings a good linear relationship between the fluorescence intensity and the concentration of arginine in the concentration range of 14.42-115.04 μM. The limit of detection is as low as 2.9 μM. A new method for quantitative determination of arginine by just measuring the fluorescence intensity of the system is established.
精氨酸是人体中的一种重要氨基酸,具有重要的临床意义。本文提出了一种基于荧光共振能量转移(FRET)的新型生物探针,可用于高效、经济地检测精氨酸。在这个生物探针系统中,带正电荷的上转换磷光体 NaYF(NYF)作为能量供体,带负电荷的金纳米颗粒(AuNP)作为能量受体。带相反电荷的供体和受体通过静电吸引作用紧密接近,导致 NYF 和 AuNP 之间发生 FRET。FRET 过程处于“开”状态,同时系统处于“关”状态,NYF 的发射光被猝灭。当带正电荷的精氨酸被加入到系统中时,精氨酸的胍基与 AuNP 结合,导致带负电荷的 AuNP 带正电荷,由于静电排斥,AuNP 从 NYF 上分离。FRET 过程被阻断,系统切换到“开”状态,因为 NYF 和 AuNP 之间的距离变长。在“开”状态下,恢复的发射光的强度与精氨酸的浓度成正比。该方法在 14.42-115.04 μM 的浓度范围内,荧光强度与精氨酸浓度之间呈现出良好的线性关系。检测限低至 2.9 μM。建立了一种通过测量系统的荧光强度来定量测定精氨酸的新方法。