A chromo- and fluorogenic sensor for probing the cancer biomarker lysophosphatidic acid

Abstract

A novel chromo- and fluorogenic sensor, 4-(4-dimethylaminostyryl)-1-hexadecylpyridinium (DSHP) for lysophosphatidic acid (LPA) was successfully developed by incorporating a long alkyl chain into the cyanine molecule. DSHP shows excellent selectivity and high sensitivity towards LPA with a detection limit of about 7.09 × 10⁻⁷ M based on electrostatic and hydrophobic interactions between the sensor and LPA. Upon addition of LPA ranging from 0 to 7.5 × 10⁻⁴ M, DSHP displays an ‘on–off–on’ fluorescence response and obvious colour change. Good linear relationships between the fluorescence intensity and LPA concentrations were achieved in the fluorescence quenching ranges of 0–28 μM and 34–52 μM, which could be attributed to the combined effects of the photoinduced electron transfer and LPA-induced aggregation of the sensor molecules.