Plasmonic Nanosensors: Design, Fabrication, and Applications in Biomedicine

Abstract

Current advances in the fabrication of smart nanomaterials and nanostructured surfaces find wide usage in the biomedical field. In this context, nanosensors based on localized surface plasmon resonance exhibit unprecedented optical features that can be exploited to reduce the costs, analytic times, and need for expensive lab equipment. Moreover, they are promising for the design of nanoplatforms with multiple functionalities (e.g., multiplexed detection) with large integration within microelectronics and microfluidics. In this review, we summarize the most recent design strategies, fabrication approaches, and bio-applications of plasmonic nanoparticles (NPs) arranged in colloids, nanoarrays, and nanocomposites. After a brief introduction on the physical principles behind plasmonic nanostructures both as inherent optical detection and as nanoantennas for external signal amplification, we classify the proposed examples in colloid-based devices when plasmonic NPs operate in solution, nanoarrays when they are assembled or fabricated on rigid substrates, and nanocomposites when they are assembled within flexible/polymeric substrates. We highlight the main biomedical applications of the proposed devices and offer a general overview of the main strengths and limitations of the currently available plasmonic nanodevices.

Application of Plasmonic Nanostructures in Molecular Diagnostics and Biosensor Technology: Challenges and Current Developments

“…The recent progress in the fabrication of advanced smart nanostructures find a widely application in the environmental and biological disciplines. In addition, the effort to fabricate nanoplasmonic biosensors based on LSPR mostly noble metal (Au or Ag), to reduce cost, expensive equipment, and these materials exhibited unmatched characteristic features that can be utilized [35]. In this regard, the optical characteristics of metallic nanostructures such as Au and Ag nanoparticles (NPs) have been developed and utilized to create simple, fast-responding, and low-cost nanodiagnostic and nanotherapeutic smart systems due to their chemical stability and biocompatibility [36].…”

Hollow Microneedle‐based Plasmonic Sensor for on Patch Detection of Molecules in Dermal Interstitial Fluid

“…AuNPs are used as optical transducers based on a phenomenon known as localized surface plasmon resonance (LSPR), which is the oscillation of the electron density on the surface of the NPs occurring at a specific excitation wavelength. [35,36] Moreover, the electromagnetic field enhancement in the surroundings of AuNPs can lead to strong fluorescence enhancement of fluorophores, if suitable conditions are satisfied. [37,38] This phenomenon goes under the name of Metal-Enhanced Fluorescence (MEF), or plasmon-enhanced fluorescence and is generally exploited to boost the limits of detection (LODs) of plasmonic biosensors down to single-molecule levels.…”

CuZn Complex Used in Electrical Biosensors for Drug Delivery Systems

“…This nanochip [ 6 , 7 , 8 ] is used as a drug reservoir, carrier, and release to control the drug load and delivery [ 9 ]. This nanochip is usually made of conductive polymers, endogenous metals, and ligands [ 10 , 11 ]. The natural conductive polymers consist of hyaluronic acid, alginate, agarose, chondroitin sulphate, carbomer, and xanthan gum [ 12 , 13 ].…”