Time–Temperature Indicator for Perishable Products Based on Kinetically Programmable Ag Overgrowth on Au Nanorods

Abstract

Food safety is a constant concern for humans. Besides adulteration and contamination, another major threat comes from the spontaneous spoilage of perishable products, which is basically inevitable and highly dependent on the temperature history during the custody chain. For advanced quality control and assessment, time-temperature indicators (TTIs) can be deployed to document the temperature history. However, the use of TTIs is currently limited by either relatively high cost or poor programmability. Here we describe a general, kinetically programmable, and cost-efficient TTI protocol constructed from plasmonic nanocrystals. We present proof-of-principle demonstrations that our TTI can be specifically tailored and thus used to track perishables, dynamically mimic the deteriorative processes therein, and indicate product quality through sharp-contrast multicolor changes. The flexible programmability of our TTI, combined with its substantially low cost and low toxicity, promises a general applicability to each single packaged item of a plethora of perishable products.

Revisiting the classification of NIR-absorbing/emitting nanomaterials for in vivo bioapplications

“…Inefficiency means higher Figure 1 The diversity on the NIR nanomaterial world. (a) nanoshells, 9 (b) nanorods, 10 (c) triangles/prisms, 11 (d) cubes and nanocages, 8 (e) nanostars, 12 (f) tubes and wires, 13 (g) dumbbells 14 and (h) urchins. 15 NIR-absorbing/emitting nanomaterials T-M Liu et al Figure 2 Absorption coefficients of major tissue components (a), fluorescence spectra of major tissue components (NADH, DNA, elastin, collagen, FAD) combined with representative fluorescence spectra of commercial quantum dots and organic fluorophores (b), luminescence spectral range of semiconductors (c), (Stokes and anti-Stokes) luminescence spectra of lanthanide doped nanoparticles, Ag 2 S and Ag 2 Se QDs (d), sensitivity of available photo-detectors (e) and available discreet (horizontal red lines) and tunable (vertical lines indicate tuning range) of state-of-the-art lasers (f).…”

Towards integrating production and consumption to reduce consumer food waste in developed countries

“…Regarding actions that can be taken by providers, some solutions call for the abolishment of best before dates to prevent people from throwing away perfectly edible food (Adam 2015) while other solutions promote innovative technology to offer more precision in detecting if food is spoilt such as temperature sensitive smart labels (Zhang et al 2013), and bio-reactive tactile tags made of gelatine that can change texture (Smithers 2016). Other solutions helped in extending product shelf-life (or percentage of shelf-life available to consumers) through packaging technology (Kirtil and Oztop 2016;Sand 2015;Smithers 2016) or though logistics and supply chain management (i.e.…”

Nanocomposite Materials for Food Packaging Applications: Characterization and Safety Evaluation

“…Due to their large surface area, nanomaterials prepare rapid visual responses when they are applied as indicators in packaging systems. They also provide a reliable indication of product quality and residual shelf life regardless of the temperature history [198]. The nanocrystal-based indicators provide a number of merits, including lower cost, ease in production, and simpler for detection by either the naked eye or a UV/Vis spectrometer [197].…”