The simple, rapid, and accurate detection of highly lethal melioidosis is crucial for early clinical diagnosis and improving cure rates. Currently, due to time consumption, low sensitivity and detection rate the existing clinical detection methods cannot satisfy the needs of clinical diagnosis. Herein, a novel self-enhanced porous hydrogel material (Au@PEI-ABEI@Pt) for ultrasensitive ECL strategy of detection B. pseudomallei was report. The novel porous hydrogel material composed of PEI-ABEI porous hydrogel, gold nanoparticles (AuNP) and platinum nanoparticles (PtNP) have large specific surface area and porous structure, which not only fix more ABEI to realize self-enhanced ECL signal amplification, but also facilitate ion diffusion and efficient utilization of catalytic materials, realizing rapid electron transfer and zero-distance catalysis, significantly improving the initial signal of ECL sensor. Moreover, the most attractive aspect is that Au@PEI-ABEI@Pt hydrogels with good biocompatibility can achieve widespread application of CRISPR/Cas12a in solid-phase carriers without affecting the sensitivity, specificity and shearing activity of CRISPR/Cas12a. After coupling with the ECL system and CRISPR/Cas12a signal amplification strategy, the Au@PEI-ABEI@Pt can achieve an ultrasensitive ECL assay of B. pseudomallei with the LOD of 5 CFU mL −1 in complex samples, with high specificity and stability to effectively classify B. pseudomallei and other Gram-negative bacteria. This study shows that the developed porous hydrogel materials not only serve as an excellent ECL signal reporter to significantly improve the detection sensitivity of ECL biosensors, but also provide a new approach for the wide application of CRISPR/Cas systems in solid-phase carriers.
A multifunctional catalytic nanomaterial (Co-MOF@AuNP@ABEI) composed of cobalt-doped metal–organic frameworks (Co-MOF), gold nanoparticles (AuNP), and N -(4-aminobutyl)- N -(ethylisoluminol) (ABEI) is reported. Co-MOF@AuNP@ABEI exhibits high synergistic and zero-distance catalytic properties, which are beneficial to the improvement of the detection sensitivity of an electrochemiluminescent (ECL) biosensor. After coupling with the ECL system and 3D magnetic walking nanomachine amplification strategy, the Co-MOF@AuNP@ABEI can achieve an ultrasensitive ECL assay of Burkholderia pseudomallei with the limit of detection (LOD) of 60.3 aM, which is 2 and 4 orders of magnitude lower than individual ECL system without the nanomachine (4.97 fM) and individual walking nanomachine (340 fM), and superior to the pathogenic bacteria analyses in the previous report. Moreover, the LOD of the proposed ECL detection system for the determination of B. pseudomallei in serum sample was as low as 9.0 CFU mL −1 . The relative standard deviations (RSD) of ECL intensity for the detection of five B. pseudomallei -spiked serum samples were 4.02%, 0.84%, 0.84%, 1.55%, and 0.21%, respectively. The recoveries of the ECL biosensor for the detection of B. pseudomallei DNA-spiked serum samples were 93.63 ~ 107.83%. Therefore, this work demonstrated that the developed multifunctional catalytic nanomaterial with synergistic and zero-distance catalytic properties can be used as excellent ECL signal reporter to improve the detection sensitivity of ECL biosensor. Graphical abstract