Herein, a versatile threshold temperature sensor based on the glass transition temperature-triggered fluorescence activation of a dye/developer duo, encapsulated in polymeric nanoparticles is reported. The emission enhancement, detectable even by unaided eye is completed within a narrow temperature range and activates at adjustable threshold temperatures up to 200 °C. Fluorescence is chosen as sensing probe due to its high detection sensitivity together with an advanced spatial and temporal resolution. The strategy is based on nanoparticles prepared from standard thermoplastic polymers, a fluorescence developer, and the commercially available Rhodamine B base dye, a well-known and widely used fluorescent molecule. By making nanoparticles of different thermoplastic polymers, fast, abrupt, and irreversible disaggregation induced fluorescence enhancement, with tunable threshold temperature depending on the nanoparticles polymer glass transition is achieved. As a proof-of-concept for the versatility of this novel family of NPs, their use for sensing the thermal history of environments and surfaces exposed to the threshold temperature is showed.

Graphene has become the focus of extensive research efforts and it can now be produced in waferscale. for the development of next generation graphene-based electronic components, electrical characterization of graphene is imperative and requires the measurement of work function, sheet resistance, carrier concentration and mobility in both macro-, micro-and nano-scale. Moreover, commercial applications of graphene require fast and large-area mapping of electrical properties, rather than obtaining a single point value, which should be ideally achieved by a contactless measurement technique. We demonstrate a comprehensive methodology for measurements of the electrical properties of graphene that ranges from nano-to macro-scales, while balancing the acquisition time and maintaining the robust quality control and reproducibility between contact and contactless methods. the electrical characterisation is achieved by using a combination of techniques, including magneto-transport in the van der pauw geometry, tHz time-domain spectroscopy mapping and calibrated Kelvin probe force microscopy. The results exhibit excellent agreement between the different techniques. Moreover, we highlight the need for standardized electrical measurements in highly controlled environmental conditions and the application of appropriate weighting functions.The unique properties of graphene 1 and the increasing demand for large-scale production were the reason for the development of various industrial methods to grow this material. One of the most promising methods is the use of CVD to grow graphene onto various metallic substrates. In CVD growth, graphene is grown on the surface of the metal after hydrocarbons decompose 2 . The most promising metal substrate used until now is Cu 3 , however graphene is currently grown also on Ni(111) 4-6 , Ru(0001) 7 , Pt(111) 8,9 , and Ir(111) 9-11 . Subsequently to the growth process, for graphene to be use in electronic applications, it needs to be transferred on an insulating substrate (i.e. Si/SiO 2 , quartz or polyethylene terephthalate (PET), which is a transparent and flexible substrate). The already happening now use of graphene in RF electronics 12 , integrated circuits 13 and optoelectronics 14 has triggered impressive progress in large-scale production, however the community still lacks standardised electrical measurements to extract useful parameters such as carrier concentration, mobility and sheet resistance, all of those are often presented as figures-of-merit of the graphene quality. Currently, the most widely used method for electrical characterisation involves magneto-transport measurements in lithographically patterned Hall bars to extract carrier concentration, mobility and resistance. However, this method is not suitable for high throughput characterisation and often the measured graphene is significantly altered due to the microfabrication processes, in which case the electrical properties of the pristine transferred graphene are different from the ones measured. An alternative method fo...