Functionalized-AgNPs for Long-Term Stability and Its Applicability in the Detection of Manganese Ions

Figure 8

Colorimetric detection of Mn²⁺ ions using the colloidal Ag-NPs: (a) UV-Vis spectra of AgNPs/PHMB without and with adding Co²⁺, Ni²⁺, and Mn²⁺ solution; (b) the UV-Vis spectra of AgNPs/PHMB solutions with different pH ranging from pH 3.5 to pH 9.0 after adding 10 mM Mn²⁺ solution; (c) UV-Vis spectra of AgNPs/PHMB in the presence of Mn²⁺ with different concentrations from 0 to 100 mM; and (d) a calibration curve for Mn²⁺ detection.

(a)

(b)

(c)

(d)