Distinct thermoresponsive behaviour of oligo- and poly-ethylene glycol protected gold nanoparticles in concentrated salt solutions

Abstract

In this work, the methoxy terminated oligo- and polyethylene glycol of different chain lengths (EGn, n = 7, 18, 45 and 136) is grafted on AuNP surfaces under conditions where they attain maximum grafting densities.

Behind the Optimization of the Sensor Film: Bioconjugation of Triangular Gold Nanoparticles with Hemoproteins for Sensitivity Enhancement of Enzymatic Biosensors

“…Thus, K M app values are obtained from the analysis of the slope and the intercept for the plot of the reciprocal of the steady state current versus the reciprocal concentration of the analyte. The effectiveness of the proposed biosensors, as evidenced by the calculated K M app values (summarized in Table 2 ), are comparable to or lower than those previously reported in the literature for similar systems that present good response for the electrocatalysis of H 2 O 2 and that involve the use of hemeproteins: Hb-cAuNP/GCE (1.2 mM) [ 21 ], Mb-AuNPs-CNs/GCE (0.3 mM) [ 60 ], and Cyt c/AuNP/carbon paste (2.3 mM) [ 61 ] within others [ 24 , 62 ]. In addition, it is noteworthy that the values presented in this work were better than those reported for nanozymes based on hemeprotein active sites for the detection of H 2 O 2 in living cells [ 63 ].…”

“…The latter are particularly interesting and, within the wide variety of systems that are reported, those based on gold nanoparticles (AuNPs) stand out [ 19 ]. This can be easily explained by considering the excellent biocompatibility of AuNPs [ 20 ], among their attractive surface chemistry and optical properties [ 21 , 22 , 23 ].…”

Biohybrid materials comprising an artificial peroxidase and differently shaped gold nanoparticles

“…In this context, several studies have reported the successful applications of anisotropic gold nanomaterials in protein electrochemistry, as they appeared to be suitable host matrices for modulating the direct electron transfer between redox-active proteins and a variety of electrodes. [28][29][30] To this end, we are currently investigating the redox and electrocatalytic response towards H 2 O 2 of FeMC6*a, when immobilized on differently shaped AuNMs or adsorbed on glassy carbon electrodes, to better clarify the relationship between AuNM anisotropy and enzyme activity.…”

“…[24][25][26] Further, the immobilization of redox-active enzymes on gold-based materials is of great interest in the eld of electrochemical biosensors, as AuNMs may act as mediators and facilitate electron exchanges between the electrode and the biomolecular component. [27][28][29][30] Within this topic, the introduction of shape anisotropy at the nanoscale has emerged as a potent way to access new properties and functionalities, enabling the exploration of complex nanomaterials across a wide range of applications. 31 Differently shaped AuNMs, like rods (AuNRs), triangular nanoprisms (AuNTs), and branched multipods like nanostars, nanowires or nanocubes, have gained interest beyond spherical goldnanoparticles (AuNPs).…”

“…16,18,[32][33][34][35] In particular, the organization and patterning of inorganic nanoparticles into surfacedeposited well-ordered nanostructures are of increasing interest in the development of biosensing devices based on redox-active enzymes. [28][29][30]36,37 In this scenario, the combination of the unique features of anisotropic AuNMs with articial metalloenzymes (ArMs) may further broaden the array of functional nanomaterials useful for the assembly of chemical, optical, and electronic devices. Diverse and powerful strategies have been developed for the design of ArMs tailored ad hoc, endowed with a reduced size, and able to perform natural and unnatural reactions.…”