Portable Dual‐Modular Immunosensor Constructed from Bimetallic Metal–Organic Framework Heterostructure Grafted with Enzyme‐Mimicking Label for Rosiglitazone Detection

Abstract

Immunosensor with photoelectrochemistry and fluorescence responsibility is widely used in biomedical detection, health monitoring, and food safety inspection. The cumbersome configuration and low integration of the current immunosensors, however, have brought challenges for their practical applications. To address these challenges, a portable and phone-APP controlled dual-modular immunosensor based on a bimetallic metal-organic framework (MOF) heterostructured photoelectrode, ZnO/NiZn-MOF/CdS, grafted with an enzyme-mimicking Au@CuO/Cu 2 O label is constructed to achieve simultaneous photoelectrochemistry and fluorescence signage. In the electrode design, the construction of a bimetallic NiZn metal-organic framework (NiZn-MOF) into the common ZnO/CdS photoresponsive structure achieves significant and stable photocurrent output under a very low-power LED light source for not only accelerating the transfer of photogenerated electrons from CdS to ZnO, but also stabilizing the holes of CdS to improve its photocorrosion resistance. After the graft of multifunctional enzyme-mimicking Au@CuO/Cu 2 O label clusters, a portable dual-modular immunosensor is built for the detection of rosiglitazone, a common antidiabetic drug and strictly restricted food residual, over a range from 10 −3 to 1 µg L −1 . This MOF-based immunosensor offers insights into highly sensitive dual-modular responsive material innovations and provides miniaturized biomedical detectors with promising commercialization potentials.

Engineering an Enzymatic Cascade Catalytic Smartphone-Based Sensor for Onsite Visual Ratiometric Fluorescence–Colorimetric Dual-Mode Detection of Methyl Mercaptan

“…Recently, the excellent catalytic activity makes artificial nanozymes to be prominent candidates for developing versatile optical sensing platforms in response to various targets because they could exploit the target as the initiator/inhibitor of its mimicking enzyme catalytic activity to yield/eliminate reactive oxygen species (e.g., • OH), resulting in optical signal changes. ,− Inspired by these points mentioned above, we here focused on integrating an artificial nanozyme into a smartphone for developing an enzymatic cascade response ratiometric fluorescence–colorimetric dual-mode POC sensor, achieving the onsite visual detection of CH 3 SH in a precise and practical way. To this end, we first employed hollow CeO 2 nanospheres to encapsulate aggregation-induced emission (AIE) tetraphenylethene (TPE) for successfully synthesizing a novel AIE fluorescence nanozyme CeO 2 @TPE with high catalase-like activity and strong blue emission at ∼441 nm.…”

Ultrasensitive Plasmonic Immunosensor Based on Hierarchically Porous Metal–Organic Framework‐Engineered Enzyme Catalysts

“…Currently, the output of immuosensor signals is dependent on the collection of light intensity or dynamic scanning via a complex optical system, limiting its practical applications in point-ofcare testing. [57,58] Regarding signal transduction of on-site detection, we fabricate a smartphone-based portable reading device to capture color transition signals occurring by means of enzymemediated surface etching of gold nanostars. The miniaturized device integrated with a smartphone, light emitting diode (light source) and microtiter plate, which had only an overall dimension of 215 mm × 130 mm × 300 mm (Figure 6c).…”

Advances in immunoassay‐based strategies for mycotoxin detection in food: From single‐mode immunosensors to dual‐mode immunosensors

“…But the dual‐mode sensor usually requires two different devices to collect the detection signal, which also increases the difficulty in practical application. Therefore, in order to meet point‐of‐care test (POCT) detection, the dual‐mode sensor is usually combined with integrated signal readers such as paper‐based microfluidic devices (Jiang, Wu, et al., 2019), microfluidic chips (Epifania et al., 2018), or intelligent integrated device (Machado et al., 2018), especially portable devices (Qileng et al., 2022). The detection cost and time can be greatly reduced by directly converting the concentration of the detection target into readable signals, and thus has been successfully verified in the detection of mycotoxins in the food and feed industry.…”