The photo-thermal lens technique is based on the measurement of the gradient temperature that is produced in an illuminated sample by laser beam as a result of non-radiative relaxation. The sensitivity of photo-thermal lens is higher than conventional absorption techniques, due to the direct measurement of absorbed energy. However, the main drawback of the photo-thermal lens technique is the inability to measure molecules that release their excess energy of absorption in the form of radiation relaxation. In fluorescence molecules, because their excess energy is released by radiation, the photo-thermal lens is insignificant. In this research, we aim to increase the photo-thermal lens sensitivity of the fluorescence molecules by selecting the appropriate acceptor for the fluorescence molecules as the donor. We investigated the effect of the presence of AuNPs on the photo-thermal lens of di-triazene (DTA) as fluorescence molecules. We observed that AuNPs enhanced the photo-thermal lens of DTA. The quantum yield of DTA was calculated to be 90.45%. The energy transfer from DTA to AuNPs occurs by fluorescence resonance energy transfer (FRET) mechanism. The FRET efficiency was 83.43%. In the presence of AuNPs, the photo-thermal lens of the DTA was amplified by four times more. The calibration curve of DTA is linear in the range of 0.1 to 110 ng/mL. The limited of detection (LOD) value of 0.08 ng/mL is calculated.

光热透镜技术基于对由于非辐射弛豫而由激光束在照明样品中产生的梯度温度的测量。由于直接测量吸收的能量，光热透镜的灵敏度高于传统的吸收技术。但是，光热透镜技术的主要缺点是无法测量以辐射松弛形式释放其多余吸收能量的分子。在荧光分子中，由于其多余的能量通过辐射释放，因此光热透镜微不足道。在这项研究中，我们旨在通过为荧光分子选择合适的受体作为供体来提高荧光分子的光热透镜灵敏度。我们调查了作为荧光分子的二三嗪（DTA）的光热透镜上存在AuNPs的影响。我们观察到AuNPs增强了DTA的光热透镜。DTA的量子产率经计算为90.45％。从DTA到AuNPs的能量转移通过荧光共振能量转移（FRET）机制发生。FRET效率为83.43％。在AuNPs的存在下，DTA的光热透镜放大了四倍。DTA的校准曲线在0.1至110 ng / mL范围内呈线性。计算出的检测极限（LOD）值为0.08 ng / mL。从DTA到AuNPs的能量转移通过荧光共振能量转移（FRET）机制发生。FRET效率为83.43％。在AuNPs的存在下，DTA的光热透镜放大了四倍。DTA的校准曲线在0.1至110 ng / mL范围内呈线性。计算出的检测极限（LOD）值为0.08 ng / mL。从DTA到AuNPs的能量转移通过荧光共振能量转移（FRET）机制发生。FRET效率为83.43％。在AuNPs的存在下，DTA的光热透镜放大了四倍。DTA的校准曲线在0.1至110 ng / mL范围内呈线性。计算出的检测极限（LOD）值为0.08 ng / mL。