A fiber optic biosensor: combination tapered fibers designed for improved signal acquisition

Development of combination tapered fiber-optic biosensor dip probe for quantitative estimation of interleukin-6 in serum samples

“…It has been demonstrated that by using a combination of two tappers the probe-to-probe signal reproducibility can be improved. 1 Further theoretical work and experimental results have also demonstrated that a combination of a taper and a constant diameter probe part further enhances the signal. 16,18,19 In this study, we have used such an evanescent wave-induced fluorescence-based combination tapered fiberoptic biosensor (CTFOB) probe.…”

“…In last two decades, significant progress has been made in the field of evanescence wave-induced fluorescence/chemiluminescencebased fiber-optic biosensors. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] Despite these advantages, the fiber-optic biosensors have been used, most of the time, only in detection of various kinds of biological analytes. 5,6,8,[11][12][13][14][15][16] Work on quantitative estimation of bioanalytes using fiber-optic sensors is very limited.…”

“…17 This is due to problem of probe-to-probe signal variability in fiber-optic systems. 1 An ideal quantifying biomarker detector requires probe-to-probe signal reproducibility in identical conditions. It has been demonstrated that by using a combination of two tappers the probe-to-probe signal reproducibility can be improved.…”

Applications of the Planar Fiber Optic Chip

“…Fluorescent fiber sensors, where the de-clad sensing region has been step-or taper-etched, exhibit a 20 to 50 fold improvement in sensitivity. Tapered fiber optic biosensor platforms have been applied to sandwich assays (Golden et al, 1992;Zhou et al, 1997), immunosensors (Anderson et al, 1993;Maragos & Thompson, 1999;Thompson & Maragos, 1996), and measuring pH. (Grant & Glass, 1997) The feasibility of collecting fluorescence using a single-mode biconical tapered fiber has also been explored.…”

“…Tapered fiber optic sensors are primarily used as fluorescence detection platforms in biochemical and clinical applications. (Anderson et al, 1993;Golden et al, 1992;Grant & Glass, 1997;Maragos & Thompson, 1999;Thompson & Maragos, 1996;Wiejata et al, 2003;Zhou et al, 1997) Previous studies, which have taken advantage of the convenience of fiber coupled instrumentation and the increased sensitivity of the total internal reflection geometry, have used a fiber optic with the cladding removed to create a sensing element around the cylindrical fiber core. The exposed core region serves as an ATR element that can be used for absorbance measurements to detect volatile organic compounds (Blair et al, 1997), probe dye solutions (Ruddy et al, 1990), monitor methane gas (Tai et al, 1987) and ammonium ion (Malins et al, 1998) concentrations, and determine solution pH using indicator doped sol-gel coatings (Gupta & Sharma, 1997;MacCraith, 1993), or an indicator doped polymer film.…”