Centro de Graduados e Investigación en Química, Instituto Tecnológico de Tijuana, A.P. 1166, Tijuana 22500, BC, Mexico.
Methods Appl Fluoresc. 2016 Nov 17;4(4):045003. doi: 10.1088/2050-6120/4/4/045003.
A new 'turn-on' Förster resonance energy transfer (FRET) nanosensor for l-tryptophan based on molecularly imprinted quantum dots (QDs) is proposed. The approach combines the advantages of the molecular imprinting technique, the fluorescent characteristics of the QDs and the energy transfer process. Silica-coated CdTe QDs were first synthesized and then molecularly imprinted using a sol-gel process without surfactants. The final composite presents stable fluorescence which increases with the addition of l-tryptophan. This 'turn-on' response is due to a FRET mechanism from the l-tryptophan as donor to the imprinted QD as acceptor. QDs are rarely applied as acceptors in FRET systems. The nanosensor shows selectivity towards l-tryptophan in the presence of other amino acids and interfering ions. The l-tryptophan nanosensor exhibits a linear range between 0 and 8 µM concentration, a detection limit of 350 nM and high selectivity. The proposed sensor was successfully applied for the detection of l-tryptophan in saliva. This novel sensor may offer an alternative approach to the design of a new generation of imprinted nanomaterials for the recognition of different analytes.
提出了一种基于分子印迹量子点（QDs）的新型 l-色氨酸Förster 共振能量转移（FRET）纳米传感器。该方法结合了分子印迹技术、QDs 的荧光特性和能量转移过程的优点。首先合成了硅涂层 CdTe QDs，然后通过无表面活性剂的溶胶-凝胶过程进行分子印迹。最终的复合材料呈现出稳定的荧光，随着 l-色氨酸的加入而增加。这种“开启”响应是由于 l-色氨酸作为供体到印迹 QD 作为受体的 FRET 机制。QDs 在 FRET 系统中很少用作受体。在存在其他氨基酸和干扰离子的情况下，纳米传感器对 l-色氨酸表现出选择性。l-色氨酸纳米传感器在 0 至 8 μM 浓度范围内呈线性，检测限为 350 nM，选择性高。该传感器成功应用于唾液中 l-色氨酸的检测。这种新型传感器可能为设计新一代用于识别不同分析物的印迹纳米材料提供一种替代方法。
