Surface‐Enhanced Raman Nanoprobes with Embedded Standards for Quantitative Cholesterol Detection

Park

et al. 2020

Small

decade, many approaches for synthesizing multifunctional NPs with combined properties have been developed, such as heterogeneous crystal growth, [3][4][5] coassembly of different building blocks, [6,7] and the template-based method involving chemical and/or physical binding. [8,9] In particular, the template-based method is advantageous for utilizing the size-and shape-dependent properties of individual NPs, [8][9][10] new properties resulting from inter-particle coupling, [8,10,11] and independently additional modification of different NPs and the template. [11,12] Among the various multifunctional NPs, magnetic-plasmonic (MP) NPs are regarded as emerging materials that are suitable for a broad range of applications, such as catalysis, [12,13] detection, [14,15] optical devices, [9,16] and therapy. [17][18][19] In particular, MP NPs simultaneously exhibiting magnetic and surface-enhanced Raman scattering (SERS) activities have been researched due to their synergistic properties in biomedical applications. [20][21][22][23][24] In detail, non-destructive and sensitive analysis of the SERS technique and separating ability based on the magnetic properties could provide convenient and significant tools in sensing of target molecules or cells. [20][21][22][23][24][25] However, it is difficult to satisfy the designing criteria for high performances in bio-applications: low remanence for preventing particle aggregation, maximized magnetic Magnetic-plasmonic nanoparticles have received considerable attention for widespread applications. These nanoparticles (NPs) exhibiting surfaceenhanced Raman scattering (SERS) activities are developed due to their potential in bio-sensing applicable in non-destructive and sensitive analysis with target-specific separation. However, it is challenging to synthesize these NPs that simultaneously exhibit low remanence, maximized magnetic content, plasmonic coverage with abundant hotspots, and structural uniformity. Here, a method that involves the conjugation of a magnetic template with gold seeds via chemical binding and seed-mediated growth is proposed, with the objective of obtaining plasmonic nanostructures with abundant hotspots on a magnetic template. To obtain a clean surface for directly functionalizing ligands and enhancing the Raman intensity, an additional growth step of gold (Au) and/or silver (Ag) atoms is proposed after modifying the Raman molecules on the as-prepared magnetic-plasmonic nanoparticles. Importantly, one-sided silver growth occurred in an environment where gold facets are blocked by Raman molecules; otherwise, the gold growth is layer-by-layer. Moreover, simultaneous reduction by gold and silver ions allowed for the formation of a uniform bimetallic layer. The enhancement factor of the nanoparticles with a bimetallic layer is approximately 10 7 . The SERS probes functionalized cyclic peptides are employed for targeted cancer-cell imaging and separation.

Section: Resultsmentioning

confidence: 78%

Section: Resultsmentioning

confidence: 99%

Design of Magnetic‐Plasmonic Nanoparticle Assemblies via Interface Engineering of Plasmonic Shells for Targeted Cancer Cell Imaging and Separation

Park

et al. 2020

Small

“…SERS nanoparticles can be utilized as optical labelling nanoprobes, similar to uorescent dyes and quantum dots, for bioimaging and biosensing with the additional advantages of ngerprint vibrational signals as a unique optical code and ultra-narrow line widths for multiplexing. 22,56,57 Typically, SERS efficiencies reach maximal values at resonant conditions, i.e., when the excitation wavelength overlaps with the LSPR wavelength, preferably in the near-infrared (NIR) biological window. However, on-resonant photogenerated heat may inevitably disturb or even destroy a biological sample or induce photobleaching of the SERS signals during the imaging process.…”

Section: Maldi Ms and Sers Based Diagnosticsmentioning

confidence: 99%

Design of plasmonic nanomaterials for diagnostic spectrometry

Gurav

Jia

et al. 2019

Nanoscale Adv.

Self Cite

“…As a consequence of tunable LSPR and photothermal effects, AuNR has been used in different biomedical applications . Mesoporous silica or polymers are commonly modified on the surface of AuNR to reduce clustering and aggregation . Nevertheless, these substances tend to separate from AuNR, resulting in poor stability and potential toxicity .…”

Section: Applications Of Graphitic Nanocapsulesmentioning

confidence: 99%

Recent Advances in Multifunctional Graphitic Nanocapsules for Raman Detection, Imaging, and Therapy

Liu

Zhu

et al. 2019

Small Methods

To date, a variety of graphitic nanomaterial-based applications have facilitated the development of biomedical applications, such as carbon quantumdot-based biosensors and imaging systems, [14][15][16][17] graphene oxide-based biosensors [18][19][20][21][22] and drug delivery systems, [20,[23][24][25] and carbon nanotube-based therapy applications. [26][27][28][29] Compared with other widely used nanomaterials, graphitic nanomaterials show superior fluorescence quenching performance, larger Raman scattering cross-sections than conventional organic Raman tags, [30] and better biocompatibility. [31] With the goal of broadening their applications, great attention has been focused on integrating graphitic materials with other inorganic nanomaterials such as noble metals [32,33] and magnetic nanomaterials. [34,35] Such graphitic nanomaterial-metal hybrid nanostructures make full use of the excellent properties of both graphitic and metal nanomaterials, and have much wider application prospect in bioanalysis. [36] However, most of the reported hybrid nanostructures, in which metal nanomaterials are exposed on the surface of graphitic nanomaterials encounter difficulty in maintaining their morphologies and stable properties under harsh conditions, such as long-term laser irradiation or strong acidic environments, which might cause inaccurate bioanalytical results and even potential biotoxicity. [37][38][39] Therefore, it is critical to prepare novel graphitic nanomaterials with superstability to meet the demands of reliable bioanalysis and biomedicine.As a type of novel graphite nanomaterial with a core-shell structure, superior physicochemical properties, good biocompatibility, superior stability, and controllable size, graphitic nanocapsules have been extensively applied in biosensing, [40,41] bioimaging, [42,43] drug delivery, [43,44] and cancer treatment. [45] Benefiting from the large surface area of the outside graphitic shell, graphitic nanocapsules supply superior nanoplatforms for drugs and targeting-molecule loading, which further broadens their biomedical applications. [42,44,46] In addition, the graphitic shell of graphitic nanocapsules possesses several unique Raman scattering bands and can act as a Raman signal tag or stable internal standard (IS) for accurate surface enhanced Raman scattering (SERS) analysis. [46,47] Particularly, the 2D band (≈2650 cm −1 ) within the cellular Raman-silent region is beneficial to avoiding the interference signals from Benefiting from their unique physicochemical properties, graphitic nanocapsules with a core-shell structure have attracted tremendous interest in bioanalysis and biomedicine recently. Using rational design, various types of graphitic nanocapsules with controllable properties are prepared to meet the demands of different biomedical applications. Graphitic nanocapsules exhibit excellent stability and superior capacity for loading nucleic acids, proteins, small molecules, and drugs due to the large specific surface area of their graphitic shells. Moreover, usin...