Kuo Chia-Hsun, Su Cheng-Kuan
Department of Chemistry, National Chung Hsing University, Taichung City 402202, Taiwan, ROC.
Anal Chem. 2025 Jan 21;97(2):1281-1290. doi: 10.1021/acs.analchem.4c05363. Epub 2024 Dec 25.
Four-dimensional printing (4DP) technologies can expand the functionality of stimuli-responsive devices to enable the integration of multiple stimuli-responsive parts into a compact device. Herein, we used digital light processing three-dimensional printing technique, flexible photocurable resins, and photocurable resins of the temperature-responsive hydrogels comprising -isopropylacrylamide (NIPAM), ,'-methylenebis(acrylamide) (MBA), and graphene for 4DP of a lab-on-valve (LOV) solid-phase extraction (SPE) device. This device featured flow manifolds and a monolithic packing connected by four near-infrared (NIR)-actuated temperature-responsive switching valves composed of a poly(NIPAM/MBA) (PNM) ball pushing a flexible membrane. NIR irradiation caused the deswelling of the PNM ball [temperature > volume phase transition temperature (VPTT) of the hydrogel], and the valve was opened to switch the flow direction. The termination of this irradiation caused the swelling of the PNM ball (temperature < VPTT of the hydrogel) to close the valve and thus recover the original flow direction to achieve the automatic NIR-actuated fluid control. The optimized 4D-printed NIR-actuated LOV-SPE device enabled a fully automatic SPE scheme coupled with inductively coupled plasma mass spectrometry for the determination of Mn, Co, Ni, Cu, Zn, Cd, and Pb ions (detection limits = 0.1,6.8 ng L). The reliability of this analytical method was validated by determining the metal ions in the four reference materials (CASS-6, SLRS-5, 1643f, and Trace Elements Urine L-2) and environmental water and human urine samples. Our results demonstrated the capability and applicability of 4DP technologies for advancing the automation of LOV-SPE schemes and related analytical methods.
四维打印（4DP）技术可以扩展刺激响应设备的功能，以便能够将多个刺激响应部件集成到一个紧凑的设备中。在此，我们使用数字光处理三维打印技术、柔性光固化树脂以及由N-异丙基丙烯酰胺（NIPAM）、N,N'-亚甲基双丙烯酰胺（MBA）和石墨烯组成的温度响应水凝胶的光固化树脂，用于阀上实验室（LOV）固相萃取（SPE）设备的4DP。该设备具有流动歧管和一个整体填料，由四个近红外（NIR）驱动的温度响应切换阀连接，这些阀由一个聚（NIPAM/MBA）（PNM）球推动一个柔性膜组成。近红外辐射导致PNM球去溶胀[温度>水凝胶的体积相变温度（VPTT）]，阀门打开以切换流动方向。这种辐射的终止导致PNM球溶胀（温度<水凝胶的VPTT）以关闭阀门，从而恢复原来的流动方向，实现近红外驱动的自动流体控制。优化后的4D打印近红外驱动的LOV-SPE设备实现了与电感耦合等离子体质谱联用的全自动SPE方案，用于测定Mn、Co、Ni、Cu、Zn、Cd和Pb离子（检测限=0.1、6.8 ng/L）。通过测定四种参考物质（CASS-6、SLRS-5、1643f和痕量元素尿液L-2）以及环境水和人类尿液样品中的金属离子，验证了该分析方法的可靠性。我们的结果证明了4DP技术在推进LOV-SPE方案和相关分析方法自动化方面的能力和适用性。
