SERS Immunoassay Based on an Enzyme-Catalyzed Cascade Reaction and Metal–Organic Framework/Alkaline Phosphatase for Ultrasensitive Detection of Adenosine Triphosphate

• DOI: 10.1021/acsami.3c13512
• Publication Date: 2023-12-19T18:57:05Z
• Authors: Yi He; Chenfeng Xie; Qianyan Zhang; Rui Cheng; Xiyu Liu; Yunli Guo; Chunhong Liu; Minghang Jiang; Mengjun Wang; Xiaojun Luo
• Keywords: Immunoassay; Adenosine Triphosphate; Metal Nanoparticles; Gold; Phenylenediamines; Alkaline Phosphatase; Spectrum Analysis, Raman; Metal-Organic Frameworks; Catalysis

Herein, an adenosine triphosphate (ATP)-induced enzyme-catalyzed cascade reaction system based on metal-organic framework/alkaline phosphatase (MOF/ALP) nanocomposites was designed to establish a surface-enhanced Raman spectroscopy (SERS) biosensor for use in rapid, sensitive ATP detection. Numerous ALP molecules were first encapsulated using ZIF-90 to temporarily deactivate the enzyme activity, similar to a lock. Au nanostars (AuNSs), as SERS-enhancing substrates, were combined with o-phenylenediamine (OPD) to form AuNSs@OPD, which could significantly improve the Raman signal of OPD. When the target ATP interacted with the MOF/ALP nanocomposites, ATP could act as a key to open the MOF structure, releasing ALP, which should further catalyze the conversion of OPD to oxOPD with the aid of ascorbic acid 2-phosphate. Therefore, with the increasing concentrations of ATP, more ALP was released to catalyze the conversion of OPD, resulting in the reduced intensity of the Raman peak at 1262 cm-1, corresponding to the level of OPD. Based on this principle, the ATP-induced enzyme-catalyzed cascade reaction SERS biosensor enabled the ultrasensitive detection of ATP, with a low detection limit of 0.075 pM. Consequently, this study provides a novel strategy for use in the ultrasensitive, rapid detection of ATP, which displays considerable potential for application in the fields of biomedicine and disease diagnosis.