Journal: Scientific Reports

Article Title: Label-free fiber-optic spherical tip biosensor to enable picomolar-level detection of CD44 protein

doi: 10.1038/s41598-021-99099-x

Figure Lengend Snippet: The geometrical profile of fiber optic spherical tip sensor (548–544 µm) used to detect CD44 protein in this work. (a,b) Two-sided profilometry of the fiber optic tips obtained from Fujikura splicer as measured by its inner microscope; where diameter on the horizontal and vertical axes (x, y) for each position along the fiber axis (z) is shown; (a) actual sensor (fabricated and used in experiments) and (b) actual sensor vs. target (i.e. designed profile for the splicing fabrication). (c,d) 3D profiles extrapolated from profilometry data by reconstructing the elliptical meshes of the tips: (c) actual sensor and (d) actual sensor vs. target; Ellipticity548-544 µm = 0.1206.

Article Snippet: Figure 1 The geometrical profile of fiber optic spherical tip sensor (548–544 μm) used to detect CD44 protein in this work. (a,b) Two-sided profilometry of the fiber optic tips obtained from Fujikura splicer as measured by its inner microscope; where diameter on the horizontal and vertical axes (x, y) for each position along the fiber axis (z) is shown; (a) actual sensor (fabricated and used in experiments) and (b) actual sensor vs. target (i.e. designed profile for the splicing fabrication). (c,d) 3D profiles extrapolated from profilometry data by reconstructing the elliptical meshes of the tips: (c) actual sensor and (d) actual sensor vs. target; Ellipticity548-544 μm = 0.1206.

Techniques: Microscopy

Journal: Scientific Reports

Article Title: Label-free fiber-optic spherical tip biosensor to enable picomolar-level detection of CD44 protein

doi: 10.1038/s41598-021-99099-x

Figure Lengend Snippet: Performance of fiber optic spherical tip sensor in terms of RI sensitivity and CD44 protein detection. (a–c) RI calibration of fiber optic spherical tip (548–544 µm) after gold coating in different sucrose concentrations: 10.49% to 13.53% in 8 steps of 0.49%, corresponding to RI values of 1.34860 to 1.35329, for a total change of 4.69 × 10 –3 RIU in steps of 5.86 × 10 –4 RIU. (a) Spectra showing the change of amplitude of the sensor in four sucrose concentrations; (b) inset showing integrated spectral response in the range where the sensor had the highest response (between 1541 and 1541.5 nm) for sensitivity estimation; (c) amplitude change as a function of RI change; curve processed with linear regression, R2 = 0.9513 with an estimated sensitivity = 95.76 dB/RIU. (d–f) CD44 protein detection by fully functionalized spherical fiber optic tip biosensor; (d) Amplitude change occurring during measurement of different concentrations of CD44 protein by the biosensor; (e) an inset showing integrated spectral response in the range where the sensor had the most sensitive response (between 1537 and 1539 nm) for LoD estimation; (f) amplitude change as a function of protein concentration; the blue line represents the fitting of the experimental data by using second-order polynomial equation.

Article Snippet: Figure 1 The geometrical profile of fiber optic spherical tip sensor (548–544 μm) used to detect CD44 protein in this work. (a,b) Two-sided profilometry of the fiber optic tips obtained from Fujikura splicer as measured by its inner microscope; where diameter on the horizontal and vertical axes (x, y) for each position along the fiber axis (z) is shown; (a) actual sensor (fabricated and used in experiments) and (b) actual sensor vs. target (i.e. designed profile for the splicing fabrication). (c,d) 3D profiles extrapolated from profilometry data by reconstructing the elliptical meshes of the tips: (c) actual sensor and (d) actual sensor vs. target; Ellipticity548-544 μm = 0.1206.

Techniques: Protein Concentration

Journal: Scientific Reports

Article Title: Label-free fiber-optic spherical tip biosensor to enable picomolar-level detection of CD44 protein

doi: 10.1038/s41598-021-99099-x

Figure Lengend Snippet: Studying specificity of functionalized fiber optic tip biosensor for CD44 protein detection by measuring control proteins (IL-4 and thrombin). The reference protein concentration used was 6 pM. ( a ) Amplitude change of the sensors when measuring target protein vs. control proteins in different concentrations; ( b ) Response of the sensors normalized to their respective RI sensitivities.

Article Snippet: Figure 1 The geometrical profile of fiber optic spherical tip sensor (548–544 μm) used to detect CD44 protein in this work. (a,b) Two-sided profilometry of the fiber optic tips obtained from Fujikura splicer as measured by its inner microscope; where diameter on the horizontal and vertical axes (x, y) for each position along the fiber axis (z) is shown; (a) actual sensor (fabricated and used in experiments) and (b) actual sensor vs. target (i.e. designed profile for the splicing fabrication). (c,d) 3D profiles extrapolated from profilometry data by reconstructing the elliptical meshes of the tips: (c) actual sensor and (d) actual sensor vs. target; Ellipticity548-544 μm = 0.1206.

Techniques: Control, Protein Concentration

Journal: Scientific Reports

Article Title: Label-free fiber-optic spherical tip biosensor to enable picomolar-level detection of CD44 protein

doi: 10.1038/s41598-021-99099-x

Figure Lengend Snippet: Currently available biosensors developed for detection of CD44 protein. Listed by the date of publication (from older to more recent).

Article Snippet: Figure 1 The geometrical profile of fiber optic spherical tip sensor (548–544 μm) used to detect CD44 protein in this work. (a,b) Two-sided profilometry of the fiber optic tips obtained from Fujikura splicer as measured by its inner microscope; where diameter on the horizontal and vertical axes (x, y) for each position along the fiber axis (z) is shown; (a) actual sensor (fabricated and used in experiments) and (b) actual sensor vs. target (i.e. designed profile for the splicing fabrication). (c,d) 3D profiles extrapolated from profilometry data by reconstructing the elliptical meshes of the tips: (c) actual sensor and (d) actual sensor vs. target; Ellipticity548-544 μm = 0.1206.

Techniques: Concentration Assay

Journal: Scientific Reports

Article Title: Label-free fiber-optic spherical tip biosensor to enable picomolar-level detection of CD44 protein

doi: 10.1038/s41598-021-99099-x

Figure Lengend Snippet: The experimental setup used for the CD44 protein measurements using a fiber optic spherical tip-based biosensor. Surface functionalization steps are shown in the zoomed area. APTMS 3-(aminopropyl)trimethoxysilane, MUA 11- mercaptoundecanoic acid , EDC 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, NHS N -hydroxysuccinimide, OBR optical backscatter reflectometry.

Article Snippet: Figure 1 The geometrical profile of fiber optic spherical tip sensor (548–544 μm) used to detect CD44 protein in this work. (a,b) Two-sided profilometry of the fiber optic tips obtained from Fujikura splicer as measured by its inner microscope; where diameter on the horizontal and vertical axes (x, y) for each position along the fiber axis (z) is shown; (a) actual sensor (fabricated and used in experiments) and (b) actual sensor vs. target (i.e. designed profile for the splicing fabrication). (c,d) 3D profiles extrapolated from profilometry data by reconstructing the elliptical meshes of the tips: (c) actual sensor and (d) actual sensor vs. target; Ellipticity548-544 μm = 0.1206.

Techniques: