Fig. 2. (A) Time-dependent fluorescence changes of the C-HCR circuit shown in Fig. 1 without analyte (a) and upon analyzing 50 nM T (b) or 50 nM I (c). (B) Fluorescence spectra generated by the C-HCR circuit upon analyzing different concentrations of I: (a) 0, (b) 1 × 10–11, (c) 5 × 10–11, (d) 1 × 10–10, (e) 5 × 10–10, (f) 1 × 10–9, (g) 5 × 10–9, (h) 1 × 10–8, (i) 5 × 10–8, and (j) 1 × 10–7 M. Inset: resulting calibration curve. (C) Calibration curves of C-HCR (a) and the conventional HCR (b) systems upon analyzing different concentrations of I. (D) Fluorescence spectra generated by the C-HCR system upon analysis of different analytes: (a) I, 10 nM, (b) IA, 10 nM, (c) IB, 10 nM, (d) IC, 10 nM, (e) no analyte. Inset: summary of the results of fluorescence spectra at λ = 520 nm. The respective system was carried out in reaction buffer for a fixed time interval of 2 h. F0 represents the original fluorescence intensity. Error bars were derived from n = 5 experiments.
