title: 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.
authors.affiliation: State Key Lab of Rare Earth Materials Chemistry and Applications, Peking University, Beijing 100871, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.forename: An-Xiang
authors.initials: AX
authors.lastname: Yin
authors.forename: Ruibin
authors.initials: R
authors.lastname: Jiang
authors.forename: Jie
authors.initials: J
authors.lastname: Rong
authors.forename: Lu
authors.initials: L
authors.lastname: Dong
authors.forename: Tian
authors.initials: T
authors.lastname: Zhao
authors.forename: Ling-Dong
authors.initials: LD
authors.lastname: Sun
authors.forename: Jianfang
authors.initials: J
authors.lastname: Wang
authors.forename: Xing
authors.initials: X
authors.lastname: Chen
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Yan
mesh_terms: D003116:Color; D004926:Escherichia coli / Q000254:growth & development; D005516:Food Microbiology / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D059022:Food Safety; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D043942:Nanotubes / Q000737:chemistry*; D012449:Safety; D012834:Silver / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D012834:Silver; D006046:Gold