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a Monte Carlo simulation. Phys Rev B 2000, 61:1965–1970.CrossRef 20. Naitoh Y, Kinoshita Y, Li YJ, Sugawara Y: The influence of a Si cantilever tip with/without tungsten coating on noncontact atomic force microscopy imaging of a Ge (001) surface. Nanotechnology 2009, 20:264011. 1–7CrossRef 21. Leng Y, Williams C, Su L, Stringfellow G: Atomic ordering of GaInP studied by Kelvin probe force microscopy. Appl Phys Lett 2004, 66:1264–1266.CrossRef Competing interests The authors declare that they have BMS345541 cell line no competing interests. Authors’ contributions ZM, JM, JT, HX, and HZ carried out the calculations, performed the experiments, and drafted the manuscript with the help of CX and JL. YL participated in the design of the study and helped to draft the manuscript. All authors read and approved the final manuscript.”
“Background Optical microcavities with tubular geometry exhibit several advantages compared to

other types of optical microcavities [1–4]. They naturally assume a hollow structure and are fully www.selleckchem.com/products/su5402.html integrative into lab-on-chip systems [5]. In the past years, rolled-up tubular microcavities have been used as cell culture devices [6, 7], microlasers [8, 9], sensors [10], and so on. Especially, rolled-up microcavities with (ultra)thin wall thickness are sensitive to tiny alterations and modifications in the vicinity Astemizole of the inner and outer tube wall surfaces [5]. Thus, the microcavities exhibit excellent

potential applications as sensors in the fields of optoelectronics [11], biosensing [6, 12], and integrated optofluidics [10, 13]. Very recently, preliminary results concerning detection of dynamic molecular processes were demonstrated on a self-rolled-up SiO/SiO2 optical microcavity with sub-wavelength wall thickness [14]. In fact, the molecule absorption/desorption are quite complex processes, and their interaction with the evanescent field is even intricate, especially in the nanoscale. Before this sensing technique can be put into practical applications like other label-free methods, more work must be done to disclose the mechanism and to exhibit the general and diverse capability of the approach. In this letter, we focus on the detection of physically and/or chemically absorbed water molecules by using a rolled-up tubular microcavity as a core component. The microcavities used in this work were prepared by releasing prestressed 33.5-nm-thick Y2O3/ZrO2 circular nanomembranes on photoresist sacrificial layers. The influence of surface composition (e.g.