generate a good signal and thus be used as excellent labels in the field of sensing
and immunochromatography (Table 3).
4.4 Upconverting Phosphor
Up-converting phosphor (UCP) is basically lanthanide-containing, ceramic sub
micro sized particles, and its composition and structure provide brilliant optical
features which emit visible light during excitation with infrared light. UCP based
ICAs have various applications those are currently limited by assay sensitivity,
however, it can increase the probability of a diagnosis by verifying the presence of
several analytes in the same sample. UCP particle is used as label to increase the
sensitivity of ICA and is also used to detect various water pollutants and diseases
like hepatitis B [75], Brucella [76], Schistosoma circulating anodic antigen [77],
interferon-c (IFN-ɣ) [78], clenbuterol [11] and target-DNA molecule [79].
5 Advantages and Disadvantages of ICA
Advantages
Disadvantages
Naked eye detection
Pre-treatment required
Rapid qualitative detection
Normally semi-quantitative
Cost effective
Cross reactivity
Longer shelf life
Unspecific adsorption
User friendly
Difficult to control capillary action
Easy to operate
Analysis time relies on surface tension, viscosity etc.
6 Application Strategies
Although a major part of the ICA based sensors used in clinical analysis, it is now
spread over the other applications, which include food analysis, detection of
pharmaceuticals, pesticides, pathogens, toxic metal ions etc. Representative
examples are given in Table 4. Different nanomaterials (e.g. AuNPs, quantum dots,
carbon-based nanoparticles, up-converting phosphors, magnetic NPs etc.) could be
used for the development of ICS, however, AuNPs are the most commonly used
nanoparticles reported in ICS devices due to its unique optical properties, very high
stability, and ease of modification and functionalization.
Immunochromatographic Strip Based Sensor for the Detection …
245
and immunochromatography (Table 3).
4.4 Upconverting Phosphor
Up-converting phosphor (UCP) is basically lanthanide-containing, ceramic sub
micro sized particles, and its composition and structure provide brilliant optical
features which emit visible light during excitation with infrared light. UCP based
ICAs have various applications those are currently limited by assay sensitivity,
however, it can increase the probability of a diagnosis by verifying the presence of
several analytes in the same sample. UCP particle is used as label to increase the
sensitivity of ICA and is also used to detect various water pollutants and diseases
like hepatitis B [75], Brucella [76], Schistosoma circulating anodic antigen [77],
interferon-c (IFN-ɣ) [78], clenbuterol [11] and target-DNA molecule [79].
5 Advantages and Disadvantages of ICA
Advantages
Disadvantages
Naked eye detection
Pre-treatment required
Rapid qualitative detection
Normally semi-quantitative
Cost effective
Cross reactivity
Longer shelf life
Unspecific adsorption
User friendly
Difficult to control capillary action
Easy to operate
Analysis time relies on surface tension, viscosity etc.
6 Application Strategies
Although a major part of the ICA based sensors used in clinical analysis, it is now
spread over the other applications, which include food analysis, detection of
pharmaceuticals, pesticides, pathogens, toxic metal ions etc. Representative
examples are given in Table 4. Different nanomaterials (e.g. AuNPs, quantum dots,
carbon-based nanoparticles, up-converting phosphors, magnetic NPs etc.) could be
used for the development of ICS, however, AuNPs are the most commonly used
nanoparticles reported in ICS devices due to its unique optical properties, very high
stability, and ease of modification and functionalization.
Immunochromatographic Strip Based Sensor for the Detection …
245