Copper ion is important in natural and biological processes. The present work describes the fabrication of a hybrid GaAs sensor for the label-free detection of copper ion in the near infrared region. The implemented sensing strategy relies on the sensitivity of the GaAs photoluminescence (PL) emission to the local environment at its surface. Specifically, GaAs (001) substrates were chemically passivated with carboxylic acid group terminated thiols, followed by the surface functionalization with artificial Me₂Cyclen cavity by a classical EDC/NHS coupling reaction. Due to a specific recognition between Me₂Cyclen and copper ions, Cu^II were coordinately captured onto the surface. The positive charges tended to deplete electrons from the near surface region and increase the band bending, leading to a PL decrease. The selectivity of the chip towards metallic ions was further confirmed by a combination of X-ray photoelectron spectroscopy, water contact angle measurements and AFM analysis. Collectively, the results described within suggest the promise of integrating well-designed organic scaffold with the unique optical properties of III–V semiconductors for a label-free detection of various analytes.

铜离子在自然和生物过程中很重要。本工作描述了混合GaAs传感器的制造，该传感器用于在近红外区域中无标记地检测铜离子。实施的传感策略依赖于GaAs光致发光（PL）发射对其表面局部环境的敏感性。具体而言，将GaAs（001）基板用羧酸基团封端的硫醇进行化学钝化，然后通过经典的EDC / NHS偶联反应用人工Me ₂ Cyclen腔进行表面官能化。由于Me ₂ Cyclen和铜离子之间的特殊识别，因此，Cu ^II被协调地捕获到表面上。正电荷趋于耗尽来自近表面区域的电子并增加能带弯曲，从而导致PL降低。X射线光电子能谱，水接触角测量和AFM分析的结合进一步证实了芯片对金属离子的选择性。总体而言，本文所述的结果表明，将精心设计的有机支架与III-V半导体的独特光学特性相集成的前景，可用于各种分析物的无标记检测。