ISSN 0030-400X, Optics and Spectroscopy, 2013, Vol. 115, No. 2, pp. 228–232. © Pleiades Publishing, Ltd., 2013. Original Russian Text © A.A. Zanishevskaya, A.V. Malinin, Yu.S. Skibina, V.V. Tuchin, M.V. Chainikov, V.I. Beloglazov, I.Yu. Silokhin, A.M. Ermakova, 2013, published in Optika i Spektroskopiya, 2013, Vol. 115, No. 2, pp. 266–271. 228 INTRODUCTION Determining the glucose concentration seems to be very important both from the viewpoint of medical diagnostics and, e.g., for estimating the quality of food products. In present-day laboratory studies, these pur- poses often require using expensive reagents and serums that are not easily available. Due to this, it seems topical to create special methods and devices based on applying new materials with the use of mini- mal quantities of preparations. In recent years, much attention has been paid to the development of materials with controlled optical properties for using them as biomedical and biochem- ical sensors. Photonic crystal waveguides (PCWs) are such materials. Photonic crystals are optical materials the dielectric permittivity of which varies with a period compared with the wavelength of light; they also have a band gap connected with the periodicity of the crys- tal in the spectrum of electromagnetic eigenstates of the crystal. A photonic crystal waveguide with a hollow core is an optical waveguide the structural shell of which is a two-dimensional photonic crystal. Such a structure is formed by a packing of round or hexagonal glass cap- illaries arranged symmetrically or asymmetrically around the core (microstructure defect corresponding to one or several glass cylinders) and creating a peri- odic two-dimensional lattice. A microphotograph of the transverse PCW cross section is presented in the insertion in Fig. 1a. The waveguide effect in a PCW is implemented owing to internal reflection from the “air–glass” peri- odic structure and creation of a photonic band gap. Figure 1 presents the transmission spectrum of a hol- low PCW (Fig. 1a) and formation scheme of a signal reflected from the wall of the waveguide (Fig. 1b). The possibility of radiation propagation along the waveguide is determined by the radiation spectral composition. Optical radiation with frequencies that lie within the band gap cannot pass through the struc- tural cladding of the waveguide, reflects from it and propagates along the PCW hollow core. Thus, the spectrum is characterized by the presence of pro- nounced maximums and minimums corresponding to photonic band gaps of the cladding. The PCW transmission spectrum is determined both by the geometric structure of the waveguide clad- ding and parameters of the medium filling the PCW core. This permits us to speak of the possibility of using the hollow-core PCW as a sensor for studied liquids and gases [1–6, 9–14]. The possibility to use PCWs as sensors was demon- strated for the first time by Y.L. Hoo et al. [13]. They detected the absorption spectra of acetylene filled the waveguide under pressure. In 2003, a group from Bath University, England [14], reported the possibility of designing a photonic crystal sensor capable of detect- ing individual molecules by their two-photon fluores- cence. In 2005, a group from Technical University of Denmark [15] demonstrated the possibility of selec- tive detection of antibodies in a hollow PCW. Two implementation protocols of PCW based biological sensors were also demonstrated in [2]. In recent years, the quantity of published works on designing PCW based fiber refractometers has increased [4, 5, 10–12]. A particular PCW class— BIOPHOTONICS Determination of Glucose Concentration in Biological Liquids Using Photonic Crystal Waveguides A. A. Zanishevskaya a , A. V. Malinin a, b , Yu. S. Skibina a, b , V. V. Tuchin a, c, d , M. V. Chainikov b , V. I. Beloglazov b , I. Yu. Silokhin b , and A. M. Ermakova b a Saratov State University, Saratov, 410012 Russia b Nanostructural Glass Technology, Research and Production Corporation, Saratov, 410033 Russia c Institute of Precision Mechanics and Control, Russian Academy of Sciences, Saratov, 410028 Russia d University of Oulu, P.O. Box 4500, Finland e-mail: zan-anastasiya@yandex.ru Received May 25, 2012 Abstract—The possibility of using hollow-core photonic crystal waveguides as biological sensors is shown. The influence of the glucose concentration in solutions introduced into the waveguide core on the transmis- sion spectrum of photonic crystal waveguides is shown. Two possible methods of determining the glucose concentration in liquids are considered, refractometric and photometric. DOI: 10.1134/S0030400X13080225