Accurate detection of protein biomarkers in complex media remains a challenge due to severe nonspecific adsorption and biofouling, and sensing interfaces that combine the high sensitivity and antifouling ability are highly desirable. Herein, an antifouling sensing interface capable of sensitively assaying immunoglobulin E (IgE) in biological samples was constructed. The sensing interface was fabricated through the self-assembly of a zwitterionic peptide and the IgE aptamer onto a macroporous Au substrate, which was electrochemically fabricated with the aid of multilayer polystyrene nanospheres self-assembled on glassy carbon electrode. Due to the huge surface area arising from porous morphology and high specificity of aptamer, the developed electrochemical biosensor exhibits ultrahigh sensitivity and selectivity towards IgE, with the linear range of 0.1–10 pg mL −1 , and a very low limit of detection down to 42 fg mL −1 . Interestingly, owing to the presence of the zwitterionic peptide, the biosensing interface can satisfyingly reduce the nonspecific adsorption and fouling effect. Consequently, the biosensor was successfully applied to detect IgE in complex biological samples, indicating great promise of this peptide-based sensing interface for antifouling assays.
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Yong Xiang,Chang-Yuan Cheng,Meng-Hao Liu,Wen-Cai Bai,Zhou-Xuan Zang,Li Xu,Yi Yu,Guo-Ji Liu
The design of an efficient adsorbent for Au(III) has remained a challenging research focus, as the adsorbent needs to overcome competition from other ions while simultaneously addressing pore blockage caused by the reduction of Au(III) to elemental gold. In this study, we report the synthesis of a hierarchically porous metal–organic frameworks (MOFs) with ultra-large pores (300 nm) using the “MOF in MOF” method. This material facilitates enhanced adsorption kinetics by increasing the rate of gold ion adsorption and effectively prevents pore blockage resulting from Au(III) reduction, enabling access to the majority of adsorption sites. Batch experiments were conducted, and various complex water mixtures, including freshwater, simulated electronic waste solution, and gold ore leachate, were tested to demonstrate the rapid extraction of trace amounts of gold by the developed adsorbent. Remarkably, without additional functionalization, the adsorbent solely based on its pore advantage achieved a gold adsorption capacity of 1184 mg/g and reached 80 % adsorption within just 5 min (C0 = 100 mg/L, V/m = 2 L/g). Furthermore, the gold recovered from the leachate of gold ore exhibited a purity of 23.8 K (99.2 % purity).