Fabrication And Application Of Novel Paper-based Platforms

The paper-based chips are widely used in the analysis field due to its features such as low cost,simple processing,easy to use and other advantages,and they provide portable platforms for clinical use,which is of great significance especially for developing countries.With the rising need of health care,point-of-care testing(POC)and on-site detection,paper-based chips aiming at obtaining more rapid,more accurate test results are in urgent need.But it is still challenging in multi targets detection,quantitative detection on paper.Herein,based on the above research background,we proposed paper-based chips aiming at multi targets detection,quantitative detection and other existing problems.Inspired by a unique approach to synthesize nano composite materials in situ on paper substrate,we improved the patterning and functionalization process of paper-based chips,developed a series of paper-based chips aiming at clinical targets,constructed two analytical platforms which have potential for clinical use.Our work includes two aspects as follow:1.Dual-functional carbon dots pattern on paper chips for Fe3+and ferritin analysis in whole bloodIn order to detect different objects at the same time,we developed a novel ?PAD,which well coupled automatic serum extraction with reliable dual mode iron health tests fluorescent analysis for Fe3+ and colorimetric ELISA for ferritin.All these functions are made available by in-situ carbon dots(CDs)and Au NPs sequential patterning techniques.For CDs immobilization,hydrothermal reaction was taken on paper,to which a patterned through-hole polydimethylsiloxane(PDMS)mask was applied.None fluorescence CDs(nF-CDs)were generated on exposed regions,while the fluorescent CDs(F-CDs)were generated simultaneously on covered regions.Sensitive serum iron quantification was realized on the F-CDs modified regions,where Fe3+ ion can selectively quench the fluorescence of F-CDs.For Au NPs immobilization,electroless plating was taken on nF-CDs modified regions.The resulting Au NPs on nF-CDs layer on one hand triggered the coagulation of blood cells and thus led to the longest ever wicking distance for serum separation,on the other hand facilitated colorimetric enzyme linked immunosorbent assay(ELISA)for detection of serum ferritin.Combining the two readings,the ?PAD can provide reliable measurement for serum iron and serum ferritin in whole blood.Furthermore,as CDs and Au NPs modified?PAD has the features of easy handling,low-cost,lightweight and disposability,it is accounting for a promising prototype for whole blood point-of-care analysis.It is of great significance for the evaluation of iron metabolism,and it also provides a new approach for the multi target detection on paper-based chips.2.Surface enhanced Raman detection of Mucin-1 protein in bloodAiming at problems of Au NPs agglomeration on paper reduces uniformity of Raman signal,we present a new strategy to deposit Au NPs in situ on filter paper to fabricate reproducible SERS active substrate.The uniformity of the substrate is carefully characterized,showing a relative standard deviation(RSD)value smaller than 8.0%,because the distribution of Au NPs is highly restricted to fibers,which is advantageous for quantitative SERS detection on paper.After equipping Au NPs with aptamer,this paper pad is endowed with ability of Mucin-1 recognition.Furthermore,this approach is capable of Mucin-1 analysis in real blood.This uniform SERS platform might provide a potential approach for quantitative analysis.