Sensitive and Homogeneous Surface‐Enhanced Raman Scattering Detection Using Heterometallic Interfaces on Metal–Organic Framework‐Derived Structure

Abstract

Here the use of heterometallic interfaces on metal–organic framework‐derived structures as surface‐enhanced Raman scattering (SERS)‐active substrates is investigated for sensitive and homogeneous SERS detection. Zeolitic imidazole framework‐67 (ZIF‐67) is grown on a conductive glass substrate via chemical bath deposition, followed by carbonization and oxidation to form ZIF‐67‐derived Co3O4 (ZIF‐67‐CO). For the sensitive and homogeneous SERS analysis, ZIF‐67‐CO is converted to the heterometallic interface Au–Ag@ZIF‐67‐derived Co3O4 (denoted as Au–Ag@ZIF‐67‐CO) via electrodeposition and successive chemical grafting. The optical properties of Au–Ag@ZIF‐67‐CO indicate a uniform and large‐scale distribution of both metals on the surface. Raman signals from the substrate are evenly enhanced based on the Raman intensity and shift mapping over a large area. Due to the multiple absorption bands of the Au–Ag@ZIF‐67‐CO substrate, signal enhancement can also be achieved with two different laser sources (532 and 785 nm) that are frequently used in SERS. As a result, concentration‐dependent and fingerprint SERS signals of small molecules such as 1,2‐bis‐(4‐pyridyl) ethylene, Nile blue A, and 1,1′‐diethyl‐2,2′‐cyanine iodide are obtained, and their signal enhancement factors are 104–105. Collectively, the use of heterometallic‐interfaced ZIF‐67‐CO will be a beneficial approach for collecting reproducible SERS signals of various target analytes.

Recent Advances in Aptamer-Based Sensors for Sensitive Detection of Neurotransmitters

“…The high biocompatibility of gold and graphene is well known [ 95 , 96 ]. In addition, the uniform size and shape distribution of nanostructures can reduce signal variability; in particular, structural uniformity in surface-enhanced Raman scattering (SERS) can significantly amplify the analyte signal [ 97 , 98 , 99 , 100 , 101 ]. On the basis of these properties, Choi et al developed a graphene/gold-hybrid SERS aptamer sensor that can detect DA by directly culturing cells on the sensor surface [ 68 ].…”

Sensitive determination of thiram in apple samples using a ZIF-67 modified Si/Au@Ag composite as a SERS substrate

“…In order to achieve the highest Raman signal for detecting both 4-ATP and thiram, the Si/Au@Ag/ZIF-67 was prepared with a precursor ratio of 1 : The AEF value of the Si/Au@Ag/ZIF-67 sensor is determined to be 3.4 × 10 6 , which is comparable to other MOF-based SERS systems. 31 Repeatability, reproducibility and stability are important requirements for ideal SERS substrates in actual applications. Fig.…”

“…Recently, some metal nanoparticle/ZIF-based substrates were reported for environmental pollution analysis. [30][31][32][33] However, it is worth mentioning that the practical application of MOF-based SERS substrates still faces challenges due to limitations in their sensitivity and stability, and further improvements are needed. In addition, controlling the accurate content and structure of MOFs outside metal nanoparticles in the fabrication process is also a demanding problem.…”

Pt3Co/Co Composite Catalysts on Porous N-Doped Carbon Support Derived from ZIF-67 with Enhanced HER and ORR Activities

“…In recent years, metal–organic frameworks (MOFs) have received much attention for their simple synthesis method, large specific surface area, high porosity, and high loading capacity. − Numerous works have been carried out to prepare heteroatom-doped porous carbon based on MOFs as self-sacrificing template precursors for enhancing the catalytic performance of carbon-loaded alloy catalysts. Zeolite imidazolate salt (ZIF-67), consisting of nitrogen-rich organic ligands and Co metal nodes that can be directly pyrolyzed to Co and N double-doped carbon, has been proved to be a promising source of cobalt and nitrogen for electrocatalysts.…”