Tuning Sensing Efficacy of Oligo(phenylenevinylene) Based Chromogenic Probes: Effect of Alkyl Substituents on Metal Ion Detection at Micelle-Water Interface.

In this work, we conducted a comparative analysis of the metal ion sensing capabilities of two pyridine-end oligo p-phenylenevinylene compounds featuring different alkyl substituents (-CH and -CH) within a micelle medium. Our findings revealed a correlation between the positioning of the probe molecules within the micelle and the length of the alkyl chains, impacting their self-assembly tendencies and optical characteristics. The compound with shorter alkyl chains demonstrated a superior affinity towards Hg ions, whereas exposure to the compound with longer alkyl substituent resulted in a color-changing response with both Cuand Hg ions. Intriguingly, the sensitivity towards Hg ions heightened with increasing alkyl chain length. This trend persisted in non-polar solvents like THF. The capacity to modulate sensing efficacy solely by adjusting the length of the alkyl chains represents a relatively uncommon occurrence in the existing literature. This discovery suggests promising prospects for engineering sensory devices equipped with adaptable sensitivity.