Morphology-Invariant Metallic Nanoparticles with Tunable Plasmonic Properties

Abstract

Current methods for tuning the plasmonic properties of metallic nanoparticles typically rely on alternating the morphology (i.e., size and/or shape) of nanoparticles. The variation of morphology of plasmonic nanoparticles oftentimes impairs their performance in certain applications. In this study, we report an effective approach based on the control of internal structure to engineer morphology-invariant nanoparticles with tunable plasmonic properties. Specifically, these nanoparticles were prepared through selective growth of Ag on the inner surfaces of preformed Ag–Au alloyed nanocages as the seeds to form Ag@(Ag–Au) shell@shell nanocages. Plasmonic properties of the Ag@(Ag–Au) nanocages can be conveniently and effectively tuned by varying the amount of Ag deposited on the inner surfaces, during which the overall morphology of the nanocages remains unchanged. To demonstrate the potential applications of the Ag@(Ag–Au) nanocages, they were applied to colorimetric sensing of human carcinoembryonic antigen (CEA) that achieved low detection limits. This work provides a meaningful concept to design and craft plasmonic nanoparticles.

Nanoplasmonic Sandwich Immunoassay for Tumor-Derived Exosome Detection and Exosomal PD-L1 Profiling

“…These results demonstrate the successful formation of Au@Ag core@shell bipyramidal nanostructures. 35,36 A significant blue-shift of the plasmonic wavelength from near-infrared (pristine AuNBPs) to visible range was observed for the Au@Ag NBPs (Figure 2a). Such a blue-shift can be tailored by altering the thickness of the coated silver layer.…”

Stable DNA Aptamer–Metal–Organic Framework as Horseradish Peroxidase Mimic for Ultra-Sensitive Detection of Carcinoembryonic Antigen in Serum

“…Moreover, the rigid structure of TDN greatly promoted the binding of the aptamer sequence at the end of the tetrahedron to the target. As a consequence, the strong molecular recognition ability and high enzyme catalytic activity ensure that the colorimetric sensing method has very high specificity and sensitivity, and the detection limit is as low as 3.3 pg/mL (superior with respect to other sensors of the same type, Table S1 ) [ 3 , 4 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ], even in clinical serum samples, so it has great application potential. In addition, the strategy proposed in this work can be extended to other aptamer sequences, so it has high universality.…”

Recent Advances in Nanomaterial‐based Optical Biosensors as Potential Point‐of‐Care Testing (PoCT) Probes in Carcinoembryonic Antigen Detection

“…Besides, the 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS) and 4‐aminoantipyrine are typical colour developing reagents that are also responsive to hydroxyl radicals but result in green and red coloured solutions respectively [78d,80c] . Otherwise, there is a collection of studies that take the advantage of nanoscale noble metals such as special optical properties due to quantum effect [83] or plasmonic effect [78c] . The gold element turns from golden in colour to become red as their sizes are scaled down [83] .…”