Kinetics-based design of a flow platform for highly reproducible on demand synthesis of gold nanoparticles with controlled size between 50 and 150 nm and their application in SERS and PIERS sensing

A study of the interaction of cationic dyes with gold nanostructures

“…Although H 2 O 2 is generally considered as an oxidizing agent, it can reduce Au( iii ) to Au(0) over a broad range of pH values, 24 favouring particle growth over homogeneous nucleation when used to reduce Au( iii ) in the presence of Au seeds. 9,25,26 The LSPR band is observed around 535 nm. Compared to 50 nm citrate-capped AuNPs ( Fig.…”

“…27 For Tris-capped AuNPs, the chelating Tris-base ligand is expected to be more tightly attracted to the AuNPs, as it is a tridentate ligand. 9 On the other hand, the citrate ligand is not as strong and the binding mode of citrate in the stabilization of AuNPs highly depends on the citrate : Au ratio, which is much more readily affected by the environment. 28 Thus, although N–Au interactions are relatively weak, having three per molecule is likely to offer better adherence and protection against an incoming dye than the citrate-capped NPs.…”

“…11 11 nm citrate-capped AuNPs were prepared with a “passivated method” in a flow reactor using a basic Au(OH) 4 − precursor reduced with citric acid, following the procedure reported by Panariello et al 10 These particles were also used as seeds to produce larger AuNPs via seeded growth protocols. 50 nm Tris-capped AuNPs were produced using a flow method developed by Panariello et al ; 9 the 11 nm citrate-capped nanoparticles were grown with the addition of Au( iii ) precursor reduced by H 2 O 2 with tris(hydroxymethyl)aminomethane (Tris-base) as the capping agent. 25 nm citrate-capped AuNPs were produced in batch with a seeded-growth approach, starting from the 11 nm citrate-capped AuNPs.…”

“…Here we build on earlier work, 7,8 investigating how interactions between dyes and AuNCs and AuNPs of various size and surface chemistry enhance UV-visible absorption, investigating how the dye–gold interaction is affected by changes in these parameters. To this aim, we synthesized AuNCs and NPs according to various protocols, 9–11 enabling control of particle features such as size and surface chemistry.…”

Importance of Monitoring the Synthesis of Light‐Interacting Nanoparticles – A Review on In Situ, Ex Situ, and Online Time‐Resolved Studies

“…Despite these efforts, exhaustive time-resolved kinetic data of nanoparticle synthesis are not widely reported. [175] As a result, nanoparticle synthesis methods are still under substantial development, with emphasis on not only improving kinetic control [23,26,62,176,177] but also reducing production cost, [46,[178][179][180] and expanding the properties/applications of the nanomaterials. [103,[181][182][183][184] In this section, we focus on the kinetic and mechanistic information obtained during the synthesis of plasmonic and optoelectronic nanomaterials in batch reactors with the aim of i) surveying time-resolved data with ex situ/in situ capabilities, ii) discussing selected studies to highlight the importance and differences between in situ and ex situ characterization, and iii) detailing the limitations of batch reactors in terms of reproducibility and time resolution.…”