Fabrication of a reusable electrochemical platform based on acid-responsive host-guest interaction with ß- cyclodextrin.

A reusable electrochemical glassy carbon electrode (GCE) platform based on the acid-responsive host-guest interaction between ß-cyclodextrin (ß-CD) and benzimidazole (BM) derivatives was developed. The ß-CD can specifically recognize the BM derivative through the acid -responsive host-guest interaction. The electrode was first modified by eletrografting to immobilize a diamine linker (Boc-EDA), resulting in GCEBoc-EDA in which one amine was used for covalent immobilization to the electrode and another Boc protected amine was used to solid-phase synthesis on following step-by-step modifications on the electrode. After deprotection of the Boc group on the GCEBoc-EDA, carbonyldiimidazole (CDI)-activated ß-CD was coupled with -NH2 on the electrode to result in GCEß-CD. Due to the nonspecific interaction, we further improved the GCEß-CD electrode by introducing immobilized poly(ethylene glycol) methyl ether (PEG-Me) to result in GCEß-CD/PEG-Me, along with optimized procedures. CV, DPV, and EIS methods were applied for recording the electrochemistry signals. We utilized GCEß-CD/PEG-Me to investigate the host-guest interaction and found the electrochemical signal exhibited dynamic behavior. The GCEß-CD/PEG-Me was able to regenerate the ß-CD surface more than 20 times after HCl acidic washes. We further investigated the interaction of carbendazim (CBZ), a commonly used fungicide in the agriculture and food industry, and observed a positive electrochemical response. The sensor design has potential applications in ensuring food safety.

Boronates as hydrogen peroxide-reactive warheads in the design of detection probes, prodrugs, and nanomedicines used in tumors and other diseases.

Hydrogen peroxide (H2O2) has always been a topic of great interests attributed to its vital role in biological process. H2O2 is known as a major reactive oxygen species (ROS) which is involve in numerous physiological processes such as cell proliferation, signal transduction, differentiation, and even pathogenesis. A plenty of diseases development such as chronic disease, inflammatory disease, and organ dysfunction are found to be relevant to abnormality of H2O2 production. Thus, imminent and feasible strategies to modulate and detect H2O2 level in vitro and in vivo have gained great importance. To date, the boronate-based chemical structure probes have been widely used to address the problems from the above aspects because of the rearranged chemical bonding which can detect and quantify ROS including hydrogen peroxide (H2O2) and peroxynitrite (ONOO-). This present article discusses boronate-based probes based on the chemical structure difference as well as reactivities to H2O2 and ONOO-. In this review, we also focus on the application of boronate-based probes in the field of cell imaging, prodrugs nanoplatform, nanomedicines, and electrochemical biosensors for disease diagnosis and treatment. In a nutshell, we outline the recent application of boronate-based probes and represent the prospective potentiality in biomedical domain in the future.

Bio-sample detection on paper-based devices with inkjet printer-sprayed reagents.

The reagent required for bio-sample detection on paper-based analytical devices is generally introduced manually using a pipette. Such an approach is time-consuming; particularly if a large number of devices are required. Automated methods provide a far more convenient solution for large-scale production, but incur a substantial cost. Accordingly, the present study proposes a low-cost method for the paper-based analytical devices in which the biochemical reagents are sprayed onto the device directly using a modified commercial inkjet printer. The feasibility of the proposed method is demonstrated by performing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) tests using simple two-dimensional (2D) paper-based devices. In both cases, the reaction process is analyzed using an image-processing-based colorimetric method. The experimental results show that for AST detection within the 0-105 U/l concentration range, the optimal observation time is around four minutes, while for ALT detection in the 0-125 U/l concentration range, the optimal observation time is approximately one minute. Finally, for both samples, the detection performance of the sprayed-reagent analytical devices is insensitive to the glucose concentration.