| Biomarkers can be used to monitor chronic diseases such as cancer,diabetes and autoimmune diseases.Therefore,the detection of biomarkers is of great significance for the diagnosis and treatment of diseases.In recent years,the development of simple and rapid biomarker detection strategies with high sensitivity is one of the goals of research by researchers.Because the resonant light(RLS)scattering method has the advantages of simplicity and high sensitivity.Therefore,in this paper,several new RLS aptasensor have been designed based on economical,high sensitivity and simple considerations,combined with molybdenum disulfide(MoS2)and Guanine nanowires(G-wire).The details are summarized as follows:1.Ultrasensitive detection of thrombin based on MoS2-aptamer biosensors by resonance light scattering techniqueThe sensor contained DNA1 and MoS2 nanosheets.The DNA1 sequence is com-posed of TBA and rDNA.In the presence of thrombin,TBA was induced to fold into a G-quartet structure.It formed a stable three-dimensional structure by an intramolecu-lar hydrogen bond,which caused the aptamer to combine with thrombin.Once the MoS2 was introduced,the rDNA can self-assemble on the surface of MoS2 to form a stable DNA1-thrombin-MoS2 complex,which increases RLS signal.The sensor shows two linear ranges of 10pM to 500pM and 1nM to 60nM,and a detection limit of 0.71pM for detection of thrombin.Our sensor is a promising tool for clinical diagnosis of thrombin in human serum.Moreover,this work can offer new opportunities for the development for detecting other proteins.2.Label-free resonance light scattering sensor for detection of miRNA by cleav-age-induced G-wire formationIn this work,we successfully constructed a high sensitivity RLS biosensor for miRNA detection using guanine nanowire-based amplification strategy.In this design,the DNA1 sequence was the complementary sequence of the target miRNA.The DNA2 sequence was composed of the complementary sequence of the DNA1 and G-rich DN A fragment.As DNA1 and DNA2 hybridize to form double-stranded DNA(dsDNA),the G-rich DNA fragment was locked.In the presence of target miRNA,the dsDNA was opened by the specific binding of DNA1 with miRNA-122.Therefore,abundant free G-rich DNA fragments in DNA2.These liberated fragments with c-myc sequence folded up into parallel-stranded G-quadruplexes and further self-assembled into long filamentous G-wires in the presence of Mg2+.These long G-wires dramati-cally raised the RLS intensity.The sensor shows a good linear ranges of 50pM to 300nM,and a detection limit of 6.1 pM for detection of miRNA-122.Our sensor is a promising tool for clinical diagnosis of miRNA-122 in real sample.3.Label-free resonance light scattering sensor for simultaneous detection of AFP and miRNAIn this work,AFP and miRNA-122 were simultaneously detected with an ap-tasensor via RLS technique.The hybridization of cDNAl and cDNA2 produced dsDNA.The aptasensor was constructed via electronic interactions between MV and dsDNA.Once AFP or miRNA-122 was introduced,one side of the dsDNA was opened by the specific binding of target-aptamer,thus changing RLS.The changed RLS signal can be used to detect AFP and miRNA-122.In the presence of AFP and miRNA-122,AFP bound to the AFP aptamer to increase the RLS signal,the RLS signal decreased when miRNA-122 bound to its complementary strand.The detection limits of AFP and miRNA-122 are 0.94μg/L and 98pM respectively,and their good linear which ranges from 5μg/L-100μg/L and 200pM-10nM are achieved using the assay.This method has potential practical applications. |
PDF Full Text Request