Adenosine-Dependent Assembly of Aptazyme-Functionalized Gold Nanoparticles and Its Application as a Colorimetric Biosensor

Juewen Liu, Yi Lu

Research output: Contribution to journalArticle

Abstract

Previous work has shown that DNAzyme-directed assembly of gold nanoparticles can be utilized to make effective colorimetric biosensors. However, the method is restricted to analytes that are directly involved in phosphodiester cleavage. To expand the methodology to a broader range of analytes, a colorimetric adenosine biosensor based on the aptazyme-directed assembly of gold nanoparticles is reported here. The aptazyme is based on the 8-17 DNAzyme with an adenosine aptamer motif that can modulate the DNAzyme activity through allosteric interactions depending on the presence of adenosine. In the absence of adenosine, the aptazyme is inactive and the substrate strands can serve as linkers to assemble DNA-functionalized 13-nm-diameter gold nanoparticles, resulting in a blue color. However, the presence of adenosine activates the aptazyme, which cleaves the substrate strand, disrupting the formation of nanoparticle aggregates. A red color of separated gold nanoparticles is observed. Concentrations of adenosine of up to 1 mM can be measured semiquantitatively by the degree of blue to red color changes or quantitatively by the extinction ratio at 520 and 700 nm. Under the same conditions, 5 mM guanosine, cytidine, or uridine resulted in a blue color only, indicating good selectivity of the sensor. The color difference can be clearly observed by the naked eye by spotting the resulting sensor solution onto an alumina TLC plate. Since aptamers that can target many classes of important analytes have already been selected, they can be adapted into aptazyme systems through rational design or further selection. Thus, colorimetric biosensors for many analytes of interest can be designed using the method presented here, regardless of whether the analytes are directly involved in the cleavage reaction or not.

Original languageEnglish (US)
Pages (from-to)1627-1632
Number of pages6
JournalAnalytical chemistry
Volume76
Issue number6
DOIs
StatePublished - Mar 15 2004

Fingerprint

Biosensors
Gold
Adenosine
Catalytic DNA
Nanoparticles
Color
Light extinction
Cytidine
Aluminum Oxide
Guanosine
Uridine
Sensors
Substrates
DNA

ASJC Scopus subject areas

  • Analytical Chemistry

Cite this

Adenosine-Dependent Assembly of Aptazyme-Functionalized Gold Nanoparticles and Its Application as a Colorimetric Biosensor. / Liu, Juewen; Lu, Yi.

In: Analytical chemistry, Vol. 76, No. 6, 15.03.2004, p. 1627-1632.

Research output: Contribution to journalArticle

@article{cbb0b0a741924942ba3356e9cbaf9ada,
title = "Adenosine-Dependent Assembly of Aptazyme-Functionalized Gold Nanoparticles and Its Application as a Colorimetric Biosensor",
abstract = "Previous work has shown that DNAzyme-directed assembly of gold nanoparticles can be utilized to make effective colorimetric biosensors. However, the method is restricted to analytes that are directly involved in phosphodiester cleavage. To expand the methodology to a broader range of analytes, a colorimetric adenosine biosensor based on the aptazyme-directed assembly of gold nanoparticles is reported here. The aptazyme is based on the 8-17 DNAzyme with an adenosine aptamer motif that can modulate the DNAzyme activity through allosteric interactions depending on the presence of adenosine. In the absence of adenosine, the aptazyme is inactive and the substrate strands can serve as linkers to assemble DNA-functionalized 13-nm-diameter gold nanoparticles, resulting in a blue color. However, the presence of adenosine activates the aptazyme, which cleaves the substrate strand, disrupting the formation of nanoparticle aggregates. A red color of separated gold nanoparticles is observed. Concentrations of adenosine of up to 1 mM can be measured semiquantitatively by the degree of blue to red color changes or quantitatively by the extinction ratio at 520 and 700 nm. Under the same conditions, 5 mM guanosine, cytidine, or uridine resulted in a blue color only, indicating good selectivity of the sensor. The color difference can be clearly observed by the naked eye by spotting the resulting sensor solution onto an alumina TLC plate. Since aptamers that can target many classes of important analytes have already been selected, they can be adapted into aptazyme systems through rational design or further selection. Thus, colorimetric biosensors for many analytes of interest can be designed using the method presented here, regardless of whether the analytes are directly involved in the cleavage reaction or not.",
author = "Juewen Liu and Yi Lu",
year = "2004",
month = "3",
day = "15",
doi = "10.1021/ac0351769",
language = "English (US)",
volume = "76",
pages = "1627--1632",
journal = "Analytical Chemistry",
issn = "0003-2700",
publisher = "American Chemical Society",
number = "6",

}

TY - JOUR

T1 - Adenosine-Dependent Assembly of Aptazyme-Functionalized Gold Nanoparticles and Its Application as a Colorimetric Biosensor

AU - Liu, Juewen

AU - Lu, Yi

PY - 2004/3/15

Y1 - 2004/3/15

N2 - Previous work has shown that DNAzyme-directed assembly of gold nanoparticles can be utilized to make effective colorimetric biosensors. However, the method is restricted to analytes that are directly involved in phosphodiester cleavage. To expand the methodology to a broader range of analytes, a colorimetric adenosine biosensor based on the aptazyme-directed assembly of gold nanoparticles is reported here. The aptazyme is based on the 8-17 DNAzyme with an adenosine aptamer motif that can modulate the DNAzyme activity through allosteric interactions depending on the presence of adenosine. In the absence of adenosine, the aptazyme is inactive and the substrate strands can serve as linkers to assemble DNA-functionalized 13-nm-diameter gold nanoparticles, resulting in a blue color. However, the presence of adenosine activates the aptazyme, which cleaves the substrate strand, disrupting the formation of nanoparticle aggregates. A red color of separated gold nanoparticles is observed. Concentrations of adenosine of up to 1 mM can be measured semiquantitatively by the degree of blue to red color changes or quantitatively by the extinction ratio at 520 and 700 nm. Under the same conditions, 5 mM guanosine, cytidine, or uridine resulted in a blue color only, indicating good selectivity of the sensor. The color difference can be clearly observed by the naked eye by spotting the resulting sensor solution onto an alumina TLC plate. Since aptamers that can target many classes of important analytes have already been selected, they can be adapted into aptazyme systems through rational design or further selection. Thus, colorimetric biosensors for many analytes of interest can be designed using the method presented here, regardless of whether the analytes are directly involved in the cleavage reaction or not.

AB - Previous work has shown that DNAzyme-directed assembly of gold nanoparticles can be utilized to make effective colorimetric biosensors. However, the method is restricted to analytes that are directly involved in phosphodiester cleavage. To expand the methodology to a broader range of analytes, a colorimetric adenosine biosensor based on the aptazyme-directed assembly of gold nanoparticles is reported here. The aptazyme is based on the 8-17 DNAzyme with an adenosine aptamer motif that can modulate the DNAzyme activity through allosteric interactions depending on the presence of adenosine. In the absence of adenosine, the aptazyme is inactive and the substrate strands can serve as linkers to assemble DNA-functionalized 13-nm-diameter gold nanoparticles, resulting in a blue color. However, the presence of adenosine activates the aptazyme, which cleaves the substrate strand, disrupting the formation of nanoparticle aggregates. A red color of separated gold nanoparticles is observed. Concentrations of adenosine of up to 1 mM can be measured semiquantitatively by the degree of blue to red color changes or quantitatively by the extinction ratio at 520 and 700 nm. Under the same conditions, 5 mM guanosine, cytidine, or uridine resulted in a blue color only, indicating good selectivity of the sensor. The color difference can be clearly observed by the naked eye by spotting the resulting sensor solution onto an alumina TLC plate. Since aptamers that can target many classes of important analytes have already been selected, they can be adapted into aptazyme systems through rational design or further selection. Thus, colorimetric biosensors for many analytes of interest can be designed using the method presented here, regardless of whether the analytes are directly involved in the cleavage reaction or not.

UR - http://www.scopus.com/inward/record.url?scp=1542408632&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=1542408632&partnerID=8YFLogxK

U2 - 10.1021/ac0351769

DO - 10.1021/ac0351769

M3 - Article

C2 - 15018560

AN - SCOPUS:1542408632

VL - 76

SP - 1627

EP - 1632

JO - Analytical Chemistry

JF - Analytical Chemistry

SN - 0003-2700

IS - 6

ER -