Chemically Induced Sintering of Nanoparticles

Abstract

We have observed solid-state growth of pre-existing silver nanoparticles (AgNPs) upon exposure to trace (ppb) concentrations of reactive gases at room temperature.T he consequent change in localized surface plasmon resonances alters the visible absorbance of dried, printed sensor spots made from inks of 10 nm-AgNPs and provides an ovel mechanism for trace detection and dosimetry of reactive gases.C olorimetric sensor arrays based on these AgNP inks offer dosimetric identification of acidic and oxidizing gases and other reactive vapors with limits of detection below ppb levels for 1h exposures.F or an array of AgNP inks with various capping agents,aunique color response pattern is observed for each specific analyte.E xcellent discrimination among 11 reactive gases was demonstrated using standard chemometric methods.T he chemically induced sintering of NPs paves the way for novel solid-state sensors for the ultrasensitive detection of reactive gases and their application to the monitoring of trace airborne pollutants.

Portable Food‐Freshness Prediction Platform Based on Colorimetric Barcode Combinatorics and Deep Convolutional Neural Networks

“…[ 7–9 ] Inspired by nature, artificial scent screening systems resembling the mammalian system (known as E‐noses, opto‐noses for olfactory, and E‐tongue for taste) have been developed for disease diagnosis [ 10 ] and detection of environmental contaminants, [ 11,12 ] explosives, [ 13 ] food, and drugs. [ 14–17 ] Cross‐reactive sensing in these artificial systems is achieved using cross‐reactive metal oxide [ 18,19 ] or colorimetric sensor arrays [ 20–23 ] that interact differentially with target molecules to generate a fingerprint pattern. Traditional statistical methods such as linear discriminant analysis (LDA), principal component analysis (PCA) and hierarchical cluster analysis (HCA) are typically used to analyze the fingerprints.…”

A universal signature in the melting of metallic nanoparticles

“…[5][6][7] Furthermore, the thermal stability of nanoparticles plays an important role in the applications derived from their physical and chemical propertiesthese range from catalysis and sintering to biomedicine, optics to chemical sensing, electronic circuits to energy storage. [8][9][10][11][12][13][14] Therefore, Lord Kelvin's question "Does the melting temperature of a small particle depend on its size?" 15 is still very actual.…”

Preise der American Chemical Society 2020

“…Seine Gruppe studiert chemische Effekte von Ultraschall, die Mechanochemie anorganischer Festkörper und chemische Sensoren. Sie beschrieben in einer Angewandte‐Chemie ‐Zuschrift das chemisch induzierte Sintern von Nanopartikeln …”