Fig. 1. Scanning electron microscopy images of CaCO₃ crystals obtained from in vitro biomineralization experiments using the slow-diffusion method over a range of dOtol1 and hOtol1 concentrations (e.g., 30 ?g/ml, 150 ?g/ml, 300 ?g/ml) grown in 2 mM, 10 mM or 25 mM CaCl₂ buffered solutions for 24 h. The scale bars on the main panels correspond to 200 ?m, while the inset scale bars correspond to 50 ?m.

Fig. 2. Micro-Raman spectra of representative altered rhombohedral crystals grown in the presence of dOtol1 (A) and hOtol1 (B) in 30 ?g/ml, 150 ?g/ml, 300 ?g/ml protein concentrations and 2 mM, 10 mM and 25 mM CaCl₂ concentrations. The measured spectra confirm that the polymorphic form of the crystals consists of calcite, and the characteristic peaks are annotated with their corresponding wavenumbers.

Fig. 3. Analysis of the average sizes (A) and numbers (B) of CaCO₃ crystals grown in the presence of 30 ?g/ml, 150 ?g/ml, 300 ?g/ml of dOtol1, hOtol1 in a bioinspired mineralization assays for 2 mM, 10 mM and 25 mM CaCl₂ concentrations along with control conditions.

Fig. 4. Stacked 2D contour maps depicting the two-photon excited fluorescence intensities of calcite crystals grown in 25 mM CaCl₂ mineralizing solution in presence of 150 ?g/ml unlabeled and 200 nM concentration of labeled dOtol1 (A), hOtol1 (B) and 250 nM free ATTO-488 NHS ester control (C) taken at several z-positions. The average power of the incident laser beam was set to 250 ?W (?ex = 800 nm). The color bar corresponds to the fluorescence intensity.

Fig. 5. Confocal laser scanning microscopy images of CaCO₃ crystals grown in the presence of 150 ?g/ml dOtol1 or hOtol1 supplemented with 200 nM ATTO-488 labeled dOtol1 and hOtol1 and 250 nM free ATTO-488 control conditions in a buffered solution of 10 mM CaCl₂ presented as bright field and fluorescence images. The scale bars correspond to 20 ?m.