Fluorescent probes for detection of Aldehyde compounds

Long-chain aldehyde compounds such as hexanal, heptanal, octanal and nonanal are regarded as potential biomarkers of many lung cancer disease and served as the important quality indicators of fat and oil products. As advantage of the hydrophobic tails of hydrocarbon chain and hydrophilic head of aldehyde, we expected that long-chained aldehydes might act as the induced-fit surfactants to form the completely self-assembling organized nanomicelle. In this research, the nanomicellar probes for specific long-chain aldehyde compounds have been achieved in the challenge concept such that among aldehydes especially long-chain aldehyde compounds, would react with Naph-NH2 to form complete micelle-like particles via hydrophobic self-packing aspect resulting in a highly efficient encapsulation and a consequent fluorescent enhancement of dye-doped nanomicelle.  Importantly, the fluorescent enhancement of Naph-NH2/CTAB/S2 at 542 nm corresponds to the amount of long-chain aldehyde added. The reaction time of probes was completed in 20 min in PBS buffer pH 7.4 with the limit of detection (LOD) of 74.38, 80.38, 80.98 and 64.09 µM for hexanal, heptanal, octanal, and nonanal, respectively. Moreover, Naph-NH2/CTAB/S2 was able to detect heptanal in blood samples with percent recovery in a range of 94-102. This sensor material was further studied on long-chain aldehyde detection in A549 cancer cells. The observation of green fluorescent in cell revealed that Naph-NH2/CTAB/S2 was internalized to the nucleus and cytoplasm. To improve the sensitivity of this sensing platform, the gelator (Gel 1) containing sucrose and long-chain hydrocarbon of lauric acid was utilized to cooperate with Naph-NH2/CTAB/S2 micellar material for long-chain aldehyde sensing aspect. Surprisingly, it showed approximately 10-fold improvement of sensitivity with LOD of 7.45, 7.59, 13.61 and 21.69 µM, respectively. Consequently, this Naph-NH2/CTAB/S2 highlights the promising selectivity and sensitivity for determination of long-chain aldehyde detection and a benefit for easy checking in real samples.