Poly(amino acid) Multilayers Modified Dendritic Mesoporous Silica Nanoparticles Achieve Effective Enzyme Stability for Ultrasensitive Immunoassay

• Published in: ACS applied materials & interfaces Vol. 12; no. 34; pp. 37906 - 37913
• Main Authors: Wang, Xuewei, Wang, Hongyu, Tang, Jinlong, Wang, Shihui, Shi, Dongjian, Shen, Heyun
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 26.08.2020
• Subjects: Amino Acids - chemistry; Biological and Medical Applications of Materials and Interfaces; Circular Dichroism; Enzyme Stability; Enzyme-Linked Immunosorbent Assay; Horseradish Peroxidase - metabolism; Hydrogen-Ion Concentration; Limit of Detection; Nanoparticles - chemistry; Polyelectrolytes - chemistry; Porosity; Silicon Dioxide - chemistry; Surface Properties; Temperature; Thermodynamics; dendritic mesoporous silica nanoparticle; signal amplification; layer by layer; poly(amino acid); horseradish peroxidase; ELISA
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.0c11523

Enzyme-linked immunosorbent assay (ELISA) is one of the most common techniques in biomedical detection; however, the poor sensitivity in early diagnosis for some diseases seriously limits its application. In this work, we developed an ultrasensitive ELISA system that is based on horseradish peroxidase (HRP)-loaded dendritic mesoporous silica nanoparticles (DMSN) modified with poly­(amino acid) multilayers (defined as DSHP). A large amount of HRP adsorption was achieved in center-radial mesoporous channels of DMSN because of the high specific surface area and large pore size, leading to significant signal amplification. Additionally, DSHP could not only effectively maintain HRP activity for at least 10 days but also provide preferable protection for HRP activity even at high temperatures or a wide pH range. Moreover, the DSHP system exhibited admirable signal amplification performance with a limit of detection of 0.667 fM and a wide detectable range from 6.67 × 10–4 to 6.67 × 105 pM, whose sensitivity was 104 times higher than that of the conventional ELISA. We believe that the DSHP will offer a new strategy for signal amplification of the ELISA system in clinical diagnosis.