Dual chemical bonding construction of electrochemical peptide sensor based on GDY/MOFs(Fe) composite for ultra-low determination of prostate-specific antigen.

A novel "double chemical bonding" electrochemical peptide biosensor 2FcP-GA-GDY(Fe)@NMIL-B was developed for highly selective, ultrasensitive, and ultrastable identification of prostate-specific antigen (PSA). The C-Fe-O chemical bond linking Fe-Graphdiyne (Fe-GDY) with NH2-MIL88B(Fe) (NMIL88B) as the first chemical bonding of electrode carrier Fe-GDY@NH2-MIL88B(Fe) (GDY(Fe)@NMIL) significantly accelerates electron transport. With glutaraldehyde (GA) as a crosslinking agent, the Schiff-base -NC- formed by GDY(Fe)@NMIL nanocomposites links the two Fc molecules labeled peptides (2FcP) as the second chemical bonding, facilitating high-density attachment of peptides to the electrode carrier in a firm manner. When the PSA analyte is introduced to identify and cleave the specific peptide, the release of ferrocene from its head leads to a decrease in the electrical signal, enabling sensitive detection. The prepared sensing platform exhibits exceptional analytical performance for PSA with an extended linear response range from 10 fg mL-1 to 50 ng mL-1. Additionally, the detection limit has been significantly reduced to an ultra-low level of only 0.94 fg mL-1, surpassing those reported in most literature by several orders of magnitude. Moreover, the 2FcP-GA-GDY(Fe)@NMIL-B sensor has excellent selectivity and stability while also showcasing great potential for practical application of PSA detection in human serum using the standard addition method.

High-throughput identification of meat ingredients in adulterated foods based on centrifugal integrated purification-CRISPR array.

Rapid, accurate, and sensitive analytical methods for the detection of food fraud are now an urgent requirement in the global food industry to ensure food quality. In response to this demand, a centrifugal integrated purification-CRISPR array for meat adulteration (CIPAM) was established. In detail, CIPAM system combines microneedles for DNA extraction and RAA-CRISPR/Cas12a integrated into a centrifugal microfluidic chip for the detection of meat adulteration. The RAA-CRISPR/Cas12a reaction reagents were pre-embedded into the different reaction chambers on the microfluidic chip to achieve the streamline of operations, markedly simplifying the detection process. The whole reaction was completed within 30 min with a detection limit of 0.1 % (w/w) in pig, chicken, duck, and lamb products. Referring to the results of the standard method, CIPAM system achieved 100 % accuracy. The automatic multiplex detection process implemented in the developed CIPAM system met the needs of food regulatory authorities.