Design strategies of AuNPs-based nucleic acid colorimetric biosensors

Nucleic acids are important biomarkers related to diseases of cancer, infectious, and genetic disorders. As a kind of indicator, gold nanoparticles (AuNPs) can generate colored signals from red to blue, which enables convenient signal readout. Based on the inherent optical properties, AuNPs are frequently used to fabricate colorimetric biosensors. Crosslinking colorimetry of polyvalent DNA-functionalized AuNPs and salt-induced colorimetry of unmodified AuNPs are two basic AuNPs-based colorimetric schemes. In order to improve such sensors sensitivity or add some specific functions, some amplification reactions or functionalized nanomaterials need to be introduced. Therefore, in this review, colorimetric biosensors with different functions and features are discussed, together with their advantages and limitations. By digging into the profound relationship between the various methods and strategies in this field, this review aims to provide a comprehensive reference outlining the general design strategies for constructing AuNPs-based nucleic acid colorimetric biosensors. (C) 2019 Elsevier B.V. All rights reserved.