Nanowire or carbon nanotube based biosensor pioneered by Charles Lieber group at Harvard quickly runs into problem when exposed to real life samples like blood. Problem is because of non specific binding and biofouling of small sensing surface. But a recent report in Nature Nanotechnology resolves this problem by integrating a microfluidic purification chip ahead of the label free nanosensor. The microfluidic purification chip has biomarker specific antibodies attached through a photocleavable linker. The chip, when exposed to blood samples purifies and concentrates the biomarker. After washing, the antibody-biomarker complex is cleaved off the chip by briefly shining light and then guided to the nanosensor chip. A second biomarker specific antibody then captures the complex and gives a response. The work was performed in the labs of Fahmy Laboratory and Reed Lab at Yale where they have previously described a new method for fabricating nanowire sensor.
The authors describe their work as representing a “Paradigm Shift” because of simplicity, speed and multiplexing capability. Last I checked, PSA could be detected from complex biological samples with sensitivity of attomolar level using Bio-barcode technology championed by Chad Mirkin and now being commercialized by Nanosphere Inc. As for integrating microfluidics with sensor, an easier to implement approach was published by James Heath at Caltech that I wrote about a while back.
I don’t see any Paradigm shift here just an incremental advance! Do you?