Título: New proposals in aqueous analysis based on the use of luminescent nanoclusters in microfluidic systems.
Resumen: This research has led to the development of a novel microfluidic flow injection biosensor. This biosensor utilizes magnetic gold nanoclusters (AuMNCs) to determine the presence of tetracyclines in water samples. These AuMNCs, which are structures composed of dozens of metal atoms surrounded by stabilizing molecules, have been modified to acquire magnetic properties. This modification allows them to be retained in the reaction/detection zone of the microfluidic system, thereby creating the biosensor. To obtain magnetic gold nanoclusters (AuMNCs), the first step was the synthesis of magnetic nanoparticles (MNPs) by the co-precipitation method. Then, AuNCs were obtained by adding an amount of MNPs and using BSA as the stabilizing agent and ascorbic acid as the reducing agent. The microfluidic system consisted of a flow injection analysis where AuMNCs were retained in the reaction/detection zone of the system to achieve the change in the luminescent signal produced by the interaction with tetracyclines. The microfluidic reactor was incorporated into the optical pathway of a conventional spectrofluorometer using a 3D-printed device to focus the excitation beam to the reaction zone of the microfluidic channel. The instrumental signal was obtained at a 22.5° angle from the excitation beam, which help perform measurements of reactions in the microfluidic channels. The best signals were achieved with a 75° rotation angle from the excitation beam. The method was compared with not retained AuMNCs and AuNCs, obtaining better results with the proposed biosensor. The system was applied to determine different tetracyclines in fish farm water, obtaining recoveries from 97 to 102%. Figure 1. Scheme of the microfluidic injection system, with a detailed image of the aligned device and the spectra obtained with AuMNs and three tetracyclines
This research has led to the development of a novel microfluidic flow injection biosensor. This biosensor utilizes magnetic gold nanoclusters (AuMNCs) to determine the presence of tetracyclines in water samples. These AuMNCs, which are structures composed of dozens of metal atoms surrounded by stabilizing molecules, have been modified to acquire magnetic properties. This modification allows them to be retained in the reaction/detection zone of the microfluidic system, thereby creating the biosensor. To obtain magnetic gold nanoclusters (AuMNCs), the first step was the synthesis of magnetic nanoparticles (MNPs) by the co-precipitation method. Then, AuNCs were obtained by adding an amount of MNPs and using BSA as the stabilizing agent and ascorbic acid as the reducing agent. The microfluidic system consisted of a flow injection analysis where AuMNCs were retained in the reaction/detection zone of the system to achieve the change in the luminescent signal produced by the interaction with tetracyclines. The microfluidic reactor was incorporated into the optical pathway of a conventional spectrofluorometer using a 3D-printed device to focus the excitation beam to the reaction zone of the microfluidic channel. The instrumental signal was obtained at a 22.5° angle from the excitation beam, which help perform measurements of reactions in the microfluidic channels. The best signals were achieved with a 75° rotation angle from the excitation beam. The method was compared with not retained AuMNCs and AuNCs, obtaining better results with the proposed biosensor. The system was applied to determine different tetracyclines in fish farm water, obtaining recoveries from 97 to 102%.
Congreso: XI NyNA 2024: International Congress on Analytical Nanoscience and Nanotechnology. September, 3-6 2024. Santiago de Compostela (Spain)
