Sensitive and Simultaneous Detection of Cardiac Markers in Human Serum Using Surface Acoustic Wave Immunosensor

Abstract

We present a rapid and sensitive surface acoustic wave (SAW) immunosensor that utilizes gold staining as a signal enhancement method. A sandwich immunoassay was performed on sensing area of the SAW sensor, which could specifically capture and detect cardiac markers (cardiac troponin I (cTnI), creatine kinase (CK)-MB, and myoglobin). The analytes in human serum were captured on gold nanoparticles (AuNPs) that were conjugated in advance with detection antibodies. Introduction of these complexes to the capture antibody-immobilized sensor surface resulted in a classic AuNP-based sandwich immunoassay format that has been used for signal amplification. In order to achieve further signal enhancement, a gold staining method was performed, which demonstrated that it is possible to obtain gold staining-mediated signal augmentation on a mass-sensitive device. The sensor response due to gold staining varied as a function of cardiac marker concentration. We also investigated effects of increasing operating frequency on sensor responses. Results showed that detection limit of the SAW sensor could be further improved by increasing the operating frequency.

Sensitive detection of carcinoembryonic antigen in exhaled breath condensate using surface acoustic wave immunosensor

“…4) applied in this work was based on the conventional sandwich immunoassay using AuNPs-antibody conjugates and subsequent mass enhancement with gold staining solutions [26]. When the pretreat process introduced above was finished, the sensing area on the sensor surface was mounted in the PDMS to form the microfluidic, which ensured the detecting system was operated in the liquid phase condition.…”

Surface acoustic wave microfluidics

“…20 Other established applications of SAW technologies include touchsensitive screens and biological/chemical sensing. 21–25 Recent research demonstrates that SAWs provide an effective means to control fluids and particles in lab-on-a-chip devices. 26 These SAW-based microfluidic devices offer the following useful and inimitable combination of features:

Simple, compact, inexpensive devices and accessories : SAW devices have been used extensively in various compact commercial electronic systems, such as cell phones (each cell phone manufactured today contains multiple SAW devices which, along with their accessories, occupy only a small portion of the phone volume).

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Cardiac troponin biosensors: where are we now?

“…This sensor represents a prototype for using acoustic wave-based sensors for biosensing; with further tweaking of the frequency and other parameters, the authors believe that this device could be successfully used for the clinical diagnosis of AMI. 61 The cardiac troponin sensors described in this paper and some other sensors are summarized in Table 2.…”