Instantaneous Attachment of an Ultrahigh Density of Nonthiolated DNA to Gold Nanoparticles and Its Applications

Zhang, Xu; Liu, Biwu; Dave, Neeshma; Servos, Mark R.; Liu, Juewen

doi:10.1021/la3035424

Cited by 166 publications

(196 citation statements)

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“…>60 poly-A DNA per 13 nm AuNP). 25,26 Without a thiol group, DNA is expected to wrap around AuNPs, 27-31 which should limit its density.…”

Section: Introductionmentioning

confidence: 99%

Parallel Polyadenine Duplex Formation at Low pH Facilitates DNA Conjugation onto Gold Nanoparticles

Huang

Liu

2016

Langmuir

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DNA-functionalized gold nanoparticles (AuNPs) have been extensively used in sensing, drug delivery, and materials science. A key step is to attach DNA to AuNPs forming a stable and functional conjugate. While the traditional salt-aging method takes a full day or longer, a recent low-pH method allows DNA conjugation in a few minutes. The effect of low pH was attributed to protonation of adenine (A) and cytosine (C), resulting in an overall lower negative charge density on DNA. In this work, the effect of DNA conformation at low pH is studied. Using circular dichroism (CD) spectroscopy, parallel poly-A duplex (A-motif) is detected when a poly-A segment is linked to a random DNA, a design typically used for DNA conjugation. A DNA staining dye, thiazole orange, is identified for detecting such A-motifs. The A-motif structure is ideal for DNA conjugation since it exposes the thiol group for directly reacting with gold surface while minimizing non-specific DNA base adsorption. For non-thiolated DNA, the optimal procedure is to incubate DNA and AuNPs followed by lowering the pH. The i-motif formed by poly-C DNA at low pH is less favorable for the conjugation reaction due to its unique way of folding. The stability of poly-A and poly-G DNA in low pH is examined. An excellent stability of poly-A DNA is confirmed, while poly-G has lower stability. This study provides new fundamental insights into a practically useful technique of conjugating DNA to AuNPs.3

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“…>60 poly-A DNA per 13 nm AuNP). 25,26 Without a thiol group, DNA is expected to wrap around AuNPs, 27-31 which should limit its density.…”

Section: Introductionmentioning

confidence: 99%

Parallel Polyadenine Duplex Formation at Low pH Facilitates DNA Conjugation onto Gold Nanoparticles

Huang

Liu

2016

Langmuir

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“…This suggests that at low pH, the buffer or salt concentration plays very minor role on the DNA adsorption behaviors. As clarified in our previous work about the fast adsorption of DNA oligomer on negatively charged citrate-capped Au nanoparticles [ [28,29]], the adenine (pKa 3.5) can be effectively protonated at pH 3.0, which decreases the electrostatic repulsion and favors DNA adsorption onto Au nanoparticles. To test the possible adsorption of other sequences, we have checked the adsorption behavior of poly-N15 (N= A, T, C, G) (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…4C). Compared with the negligible Raman signals on the control electrode (curve b), the typical peaks at 1595, 1378, and 1146 cm -1 can be assigned to vibration of a ring mode, a ring mode/ribose CH, OH bending, and nonbridging phosphate of ATP [ [28,33]] (curve a). Notably, no citrate ions was detected to gold electrode even at an ultrahigh concentration (250 mM), according to the absence of its typical C=O vibration (~1750 cm −1 ) in Raman spectrum.…”

Section: Resultsmentioning

confidence: 99%

“…The DNA density and conformation can be tuned by changing the length of the poly-adenine block, where a longer poly-adenine block should produce more sparsely distributed DNA. The attachment of non-thiolated DNA has also recently been demonstrated on gold nanoparticles (AuNPs) using a similar poly-adenine anchoring strategy [26][27][28]. In addition to these advantages, the cost of thiolated DNA is about ten to twenty-fold higher compared to the non-thiolated counterpart.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, our group has studied the adsorption of DNA by citrate-capped AuNPs, where quick DNA loading was achieved in a few minutes at low pH [28,29]. The reason for the low pH strategy 4 to work is because of protonation of the adenine and cytosine bases, reducing the electrostatic repulsion with the negatively AuNP surface, which is capped by citrate.…”

Section: Introductionmentioning

confidence: 99%

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Fast assembly of non-thiolated DNA on gold surface at lower pH

Jiang¹,

Materón²,

Sotomayor³

et al. 2013

Journal of Colloid and Interface Science

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In a typical protocol for attaching DNA to a gold electrode, thiolated DNA is incubated with the electrode at neutral pH overnight. Here we report fast adsorption of non-thiolated DNA oligomers on gold electrodes at acidic pH (i.e., pH ~3.0). The peak-to-peak potential difference and the redox peak currents in typical cyclic voltammetry of [Fe(CN)6] 3-are investigated to monitor the attachment. Compared with incubation at neutral pH, the lower pH can significantly promote the adsorption processes, enabling efficient adsorption even in 30 min. The adsorption rate is DNA concentration-dependent, while the ionic strength shows no influence. Moreover, the adsorption is base-discriminative, with a preferred order of A >C>>G, T, which is attributed to the protonation of A and C at low pH and their higher binding affinity to gold surface. The immobilized DNA is functional and can hybridize with its complementary DNA but not a random DNA. This work is promising to provide a useful time-saving strategy for DNA assembly on gold electrodes, allowing fast fabrication of DNA-based biosensors and devices.3

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Protein‐Mimicking Nanoparticles in Biosystems

Fan

2022

Advanced Materials

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Up to now, most protein-mimicking NPs can be classified into one of the four categories: 1) enzyme-like catalytic activities have been identified among a wide variety of nanomaterials including noble-metal-, metal-oxide-, carbon-, and metal-organic framework (MOF)-based nanozymes. Similar to engineered enzymes, the catalytic properties of nanozymes can be finetuned by the change of composition and surface modification. In addition, dual-or multiple-enzyme mimetic activities can be integrated into one type of NPs. [3,4] 2) Fluorescent NPs such as quantum dots (QDs), upconversion NPs (UCNPs), aggregation-induced emission (AIE) NPs, and semiconducting polymer NPs (SPNPs)/polymer dots (Pdots), can serve as attractive alternatives or even better replacement of fluorescent proteins, bringing broader benefits for bioimaging and light-activated therapy. NPs of this category possess high fluorescence intensity, tunable fluorescence wavelengths, and high photostability. These unique optical properties make them ideal fluorophores for long-term tracking and simultaneous monitoring of multiple biological species. [5] Moreover, some types of fluorescent NPs can be tuned to emit in the near-infrared (NIR) window, providing great advantages for deep-tissue imaging. [6] 3) More and more studies reveal that certain types of NPs show high affinity binding to specific proteins or DNA sequences. Such interaction leads to the utilization of NPs for protein or DNA recognition, and may actively alter cellular signaling and communication when introduced into living systems. [7,8] Alternatively, the DNA binding capacity can be used for the docking of DNA strands for the assembly of supramolecular structures. [9] 4) The bottom-up construction of NPs has created a diversity of nanostructures with close similarities in both morphology and function to natural protein scaffolds. NPs based on DNA strands, polymers, or carbon nanotubes (CNTs) can form membrane-embedded hollow structures (nanopores) analogous to biological ion channels. Extracellular or intracellular scaffold-mimicking NPs have been designed to mediate cell-cell contact, communication, and signaling cascade. [10,11] Besides, curved nanostructures can mimic membrane sculpting proteins to mediate membrane extrusion or invagination. [12,13] Compared with natural proteins, the abovementioned categories of protein-mimicking NPs are cost-efficient, physically, and chemically stable, and can be constructed with more versatility for translating into a broad range of applications.Proteins are essential elements for almost all life activities. The emergence of nanotechnology offers innovative strategies to create a diversity of nanoparticles (NPs) with intrinsic capacities of mimicking the functions of proteins. These artificial mimics are produced in a cost-efficient and controllable manner, with their protein-mimicking performances comparable or superior to those of natural proteins. Moreover, they can be endowed with additional functionalities that are absent in natural proteins, such ...

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Instantaneous Attachment of an Ultrahigh Density of Nonthiolated DNA to Gold Nanoparticles and Its Applications

Cited by 166 publications

References 50 publications

Parallel Polyadenine Duplex Formation at Low pH Facilitates DNA Conjugation onto Gold Nanoparticles

Parallel Polyadenine Duplex Formation at Low pH Facilitates DNA Conjugation onto Gold Nanoparticles

Fast assembly of non-thiolated DNA on gold surface at lower pH

Protein‐Mimicking Nanoparticles in Biosystems

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