Liu Dan Yu,Pan Xue,Zhang Jingli,Tong Yinjia,Zhang Yixuan,Yu Yanjing,Zhang Qingda,Huang Mengfei,Yiheng Gao,Jie Li,Qufu Wei,Pengfei Lv
The rapid development of intelligent wearable devices and health monitoring equipment demands bio-based materials that integrate multiple functions with enhanced durability. Herein, this work is an first attempt to develop flexible electromagnetic shielding and stress-strain sensing based on a composite of polydopamine (PDA) modified-MXene (p-MXene) film with waterborne polyurethane (WPU)/bacterial cellulose (BC) film. The durable p-MXene@WPU/BC composite films are found to demonstrate excellent mechanical properties (370 MPa) and stable interfacial adhesion, attributing to the interlocking network structure between WPU and WBC and the strong hydrogen bonding between p-MXene layer and WPU/BC layer. The resultant composite film displays remarkable mechanosensing performance, facilitating the accurate and reliable detection of human physiological signals. Importantly, the prepared composite film could effectively reflect and absorb electromagnetic waves through the high conductivity of p-MXene layer and the staggered nanonetwork structure of WPU/BC layer, thus achieving a shielding effect of up to 72 dB. As proof-of-concept illustrations, it is noteworthy that the electromagnetic shielding efficacy displays a dynamic interaction with the strain sensing performance during the stretching process, which is primarily attributed to the moderating effect of the efficient attachment and parallel-aligned structure of p-MXene nanosheets. The research herein can offer new perspectives on the development of advanced bio-based multiple functions materials and dynamic perceptual interaction and smart wearables.
Chun Yang,Zunquan Zhao,Qichen Yang,Yanjun Fang,Jingran Sun,Liqin Du,Yonghui Wang,Xiaoli Li,Nan Su,Jin Wu,Mingzhu Liu,Ying Liu,Jialei Bai
MXene-based fluorescent aptasensors detect targets through MXene-mediated adsorption of labeled aptamer probes and subsequent target-induced release of the probe signals, providing a promising programmable detection approach. However, their sensitivity is limited by the low signal output per aptamer or the incomplete quenching of the ultrabright aptamer probes by MXene. This study proposes an advanced MXene-based detection platform that addresses these challenges through material engineering and innovative sensing strategies. Polydopamine-mediated interface engineering endows monolayer MXene nanosheets (p-MXene) with excellent nanocolloidal stability and dynamic reversible internanosheet networks. While concentrated, it exhibits complete self-settling and adhesion behavior with a tendency toward spontaneous solid–liquid separation. This characteristic enhances the adhesion of the p-MXene/aptamer nanocomposites during mild centrifugal precipitation without compromising the target-induced aptasensing capability of these nanocomposites. Free from incomplete quenching concerns, the platform leverages ratio-controlled click chemistry to synthesize red fluorescence quantum dot-aptamer conjugates (RQDs@APT) for maximum signal per aptamer. The p-MXene/RQDs@APT achieves near-zero-background specific detection of aflatoxin B1 with a high signal-to-noise ratio and outstanding reproducibility. It shows a linear range of 0.90–35 μg/kg and a detection limit of 0.27 μg/kg in real food samples, while supporting visual detection. The aptasensor is easy to rapidly assemble, and each module has long-term storage stability. The azide-modified aptamer lyophilized powders can be stored and replaced separately, enabling the platform to be easily expanded to detect other targets. The platform has demonstrated satisfactory performance in detecting deoxynivalenol, ochratoxin A, zearalenone, and fumonisin B1. This sensitive, robust, and universal technology shows great potential for various detection applications.
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