Photoluminescence chemical sensing

Semiconductor band-gap luminescence results from excited electrons recombining with electron vacancies, holes, across the band gap of the semiconductor material. Electrons can be excited across the band gap of a semiconductor by absorption of light, as in photoluminescence (PL), or injected by electrical bias, as in electroluminescence (EL). Both types of luminescence have been used in chemical sensing applications [1,3]. 

Photoluminescence spectroscopy is a well-established technique and a very powerful analytical method, which has proven its advantages in chemical sensing. Due to its high sensitivity and reliability it can provide fast and precise information about recognition by variations in the optical signal. Additionally, progress in materials technology as well as advances in microelectronics and computer science have... 

An attractive alternative to organic fluorophores in formulated polymeric sensor films for chemical detection is to use inorganic luminescent materials. Semiconductor nanocrystals have a dramatically improved photostability and are attractive as luminescent labels.1415 However, some nanocrystals also exhibit photoluminescence (PL) that is sensitive to the local environment. For example, it was observed that PL of CdSe nanocrystals incorporated into polymer thin films responded reversibly to different gases.16 Because in sensing applications nanomaterials bring previously unavailable capabilities1719 and unexpected results,20 23 we explored the environmental sensitivity of semiconductor nanocrystals upon their incorporation in different rationally selected polymeric matrices.24 26... 

Laminack WI, Gole JL (2013) Light enhanced electron transduction and amplified sensing at a nanostructure modified semiconductor interface. Adv Funct Mater 23(47) 5916-5924 Lauerhaas JM, Sailor MJ (1993) Chemical modification of the photoluminescence quenching of porous silicon. Science 261(5128) 1567-1568... 

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