Quantum Dot-PNA Conjugates for Target-Catalyzed RNA Detection

Abstract

Detection of pathogenic nucleic acids remains one of the most reliable approaches for the diagnosis of a broad range of diseases. Current PCR-based methods require experienced personnel and cannot be easily used for point-of-care diagnostics, making alternative strategies for the sensitive, reliable, and cost-efficient detection of pathogenic nucleic acids highly desirable. Here, we report an enzyme-free method for the fluorometric detection of RNA that relies on a target-induced fluorophore transfer onto a semiconductor quantum dot (QD), uses PNA probes as selective recognition elements and can be read out with simple and inexpensive equipment. For QD-PNA conjugates with optimized PNA content, limits of detection of dengue RNA in the range of 10 pM to 100 nM can be realized within 5 h in the presence of a high excess of noncomplementary RNA.

Templated chemistry for bioorganic synthesis and chemical biology

“…The setup allowed the detection of 500 attomol RNA target. Recently, we used the reaction in the RNA target–promoted transfer of fluorophores onto semiconductor quantum dots . We showed that the acyl transfer reaction is not restricted to PNA‐based reaction systems but also proceeds with reactive DNA conjugates …”

“…Recently, we used the reaction in the RNA target-promoted transfer of fluorophores onto semiconductor quantum dots. 103,104 We showed that the acyl transfer reaction is not restricted to PNA-based reaction systems but also proceeds with reactive DNA conjugates. 105 At the outset of this chapter, I described the idea of developing systems that read RNA and translate the recognition event into a reaction product that interferes with cellular processes.…”

Electrostatic Repulsion Controls Efficiency of Cu‐Free Click‐Reaction with Azide‐Modified Semiconductor Quantum Dots

“…Although several papers demonstrate utilization of CuAAC for QDs conjugation, this method requires fine tuning of Cu catalyst concentration and other reaction parameters for different QDs samples. Nowadays, SPAAC reaction seems to be the most perspective method for QDs conjugation because of its relative simplicity and the absence of Cu ions …”

“…Nowadays, SPAAC reaction seems to be the most perspective method for QDs conjugation because of its relative simplicity and the absence of Cu ions. [19][20][21][22][23] However, the main disadvantage of SPAAC reaction is its lower reaction rate compared to CuAAC, especially at low concentration of the reagents. From the other side, being pHindependent SPAAC provides excellent opportunity to study the influence of surface charge or zeta potential (which is an important parameter of colloidal systems [24] ) on the efficiency of NPs conjugation with charged biomolecules.…”

Turn On of a Ruthenium(II) Photocatalyst by DNA‐Templated Ligation

“…[1][2][3][4] This has stimulateds ignificant efforts in the area, with agrowing number of reactions extending the breadtha nd scope of templated transformations. Prominent examples include nucleophilic reactions, [5][6][7] olefinations, [8][9] Staudinger reactions, [2,[10][11][12] conjugate additions, [13] native chemical ligations or acyl transfers, [14][15][16][17] and cycloadditions. [18][19][20] Important applications of these reactions include the synthesis of small molecule libraries,n ucleic acid sensing or drug uncaging.…”