Applications of gold nanoparticles in virus detection

Draz, Mohamed Shehata; Shafiee, Hadi

Interestingly, the enhanced surface area-to-volume ratio of AuNPs has allowed them to further act as exquisite scaffolds for biorecognition and detection reactions (Fig. 2 ); in addition, it has granted these structures unprecedented capabilities for bioimmobilization, which is a basic principle of most AuNP-based diagnostic designs. By coupling these bioimmobilization and signal transduction functions, AuNPs can achieve virus detection with highly improved analytical sensitivity and specificity. Furthermore, the direct increase in loading efficiency allows new possibilities of controlled multifunctionalization with different biomolecules. Based on this principle, developed AuNP tags are characterized by enhanced reactivity and stability. Increased loading efficiency also allows the design of new probes modified with multiple structures for biotargeting (e.g., antibodies and DNA), together with other signal amplification structures (e.g., enzymes and DNA oligonucleotides) [69, 76, 77, [96] [97] [98] , both types of which are stridently included in the development of new diagnostic schemes and designs. For example, the AuNP- Figure 2 . A generalized scheme for the basic characteristics and functions of AuNPs applied in virus detection. The size and metal nature of AuNPs are the key characteristics that enable them to directly transduce multiple types of signals, including optical, catalytic and electrical signals that can be detected by dynamic light scattering (DLS), localized surface plasmon resonance (LSPR), surface-enhanced Raman scattering (SERS), ultraviolet-visible (UV-vis) spectroscopy, fluorometry and other electrochemical analysis techniques. In addition, AuNPs act as nanoparticulate tags to enhance the signal detection of several analytical techniques, such as quartz crystal microbalance (QCM), atomic force microscopy (AFM), and inductively coupled plasma mass spectrometry (ICP-MS). Their large surface area-to-volume ratio is known to permit them to function as an excellent scaffold for bioimmobilization and target-probe interactions with highly enhanced specificity and sensitivity.