Fig. 1. Flouresence excitation (a and a) and emission (b and b) spectra of PAN (4×10−5 M) in the absence (a and b) and presence (a and b) of 0.3gml−1 Sn(II). Conditions: [AOT] = 8×10−4 M, [Triton X-100] = 0.025% (v/v), pH 3, λex = 300 nm, λem = 360 nm.