BACKGROUND: Formaldehyde is widely acknowledged as carcinogen, but as an important organic reagent, it has also been widely employed in the fields of chemical synthesis, industrial production and biomedicine. It is therefore of great practical significance for the detection of formaldehyde in food, clothing, daily necessities, construction materials and environments.
METHODS: The two silicon QDs, that is, DAMO-Si-QDs (with
N-[3-(Trimethoxysilyl) propyl]ethylenediamine as silicon source) and APTMS-Si-QDs (with (3-Aminopropyl) trimethoxysilane as silicon source) as the fluorescence probe to detect formaldehyde in both water and organic phases
RESULTS: Silicon QDs prepared by different silicon sources exhibit obvious difference in their tolerances to the environment and the responses to formaldehyde. However，APTMS-Si-QDs shows better selectivity in both water and organic phases. In Tris-HCl solution (20.00mmol•L-1, pH=5), the formaldehyde concentration maintains excellent linear relationship with the fluorescence intensity of APTMS-Si-QDs in the range of
3.125×10-7-3.125×10-5 mol•L-1, with correlation coefficient R2= 0.9998.
In methanol, the formaldehyde concentration maintains excellent linear relationship with the fluorescence intensity of APTMS-Si-QDs in the range of
1.563×10-7-3.125×10-5 mol•L-1, with correlation coefficient R2= 0.992.
CONCLUSION: It is found that DAMO-Si-QDs show poor response to the presence of formaldehyde, while APTMS-Si-QDs got strong, sensitive and selective response to that in both aqueous and organic phases. In the Tris-HCl buffer
(20 mmol•L-1, pH=5), the linear range for formaldehyde detection reaches
3.125×10-7-3.125×10-5 mol•L-1, and for the detection in organic phase, the linear range reaches 1.563×10-7-3.125×10-5 mol•L-1, in methanol solution. The paper provides a sensitive, selective and simple means for formaldehyde detection in both aqueous and organic phase.