abstract
A new sensitive and selective fluorescence sensor for the detection of pyrophosphate (PPi) in aqueous
media based on the Fe3+ decorated cysteamine CdS QDs ([Cys-CdS QDs]–Fe3+) was proposed. The presence
of PPi can induce the fluorescence quenching of [Cys-CdS QDs]–Fe3+ due to the high formation constants
between the phosphate group and Fe3+. Because the complex between Fe3+ and PPi acts as an
efficient quencher, the concentration of PPi can be evaluated by tracking the degree of fluorescence
quenching. The fabricated sensor was optimized to obtain the best sensor selectivity and sensitivity.
Under optimal conditions, a linear relationship between the fluorescence response and the concentration
of PPi was established in the range of 0.5–10 lM. The limits of detection and quantitation for PPi were
found to be 0.11 and 2.78 lM, respectively. Furthermore, the proposed sensor exhibited high selectivity
toward PPi relative to other common anions. The proposed sensor was successfully applied to the detection
of PPi in urine samples with satisfactory results.