The formation of binary and ternary complexes of poly(acrylic acid) (PAA) with N,N,N,N-dodecyltrimethylammonium chloride (DTAC) and/or Cu2+ ions is investigated in dilute aqueous solution through turbidimetry, viscometry, and pyrene fluorescence probing. It is shown that the PAA-DTAC and PAA-Cu2+ complexation as well as the formation of ternary PAA-DTAC-Cu2+ complexes are controlled from the pH of the aqueous solution. A pronounced quenching of the emission of pyrene is observed when ternary PAA-DTAC-Cu2+ complexes are formed, as a result of the close proximity of Cu2+ ions (complexed along the polymer chain) and the probe (solubilized in the hydrophobic mixed polymer-surfactant aggregates), as indicated from the corresponding Stern-Volmer plots. A significant quenching is also observed when poly(sodium styrene sulfonate) is used instead of PAA, indicating that electrostatically bound Cu2+ ions are still effective quenchers of the emission of the probes under similar conditions. Finally, it is demonstrated that the formation-deformation of the ternary PAA-DTAC-Cu2+ complexes upon changing pH may act as a pH-controlled "on-off' switch of the emission of pyrene in aqueous solution.